[
  {
    "sku": "NU20-530-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/530 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 530,
    "D_mm": 780,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3740,
    "static_load_kN": 7350,
    "fatigue_load_limit_kN": 550,
    "max_rpm": 1000,
    "reference_speed_rpm": 670,
    "limiting_speed_rpm": 1000,
    "weight_g": 253000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU20-530-ECMA is the 530 mm bore entry in the NU2000 range: a 530×780×145 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 3740 kN / C0 7350 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 125.0 mm and the catalogue mass 253000 g; at 3740 kN dynamic rating this is roughly 7.06 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/530, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/530 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 145 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 3740/7350 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-530-ECMA?",
        "a": "SKF NU 20/530 ECMA is a single-row caged cylindrical roller bearing with 530 mm bore, 780 mm OD and 145 mm width per ISO 15. SKF lists C 3740 kN, C0 7350 kN, Pu 550 kN, reference speed 670 r/min and limiting speed 1,000 r/min, mass about 253000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-530-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-530-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-530-ECMA",
      "SKF NU 20/530 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-560-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/560 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 560,
    "D_mm": 820,
    "B_mm": 150,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3800,
    "static_load_kN": 7650,
    "fatigue_load_limit_kN": 560,
    "max_rpm": 1000,
    "reference_speed_rpm": 630,
    "limiting_speed_rpm": 1000,
    "weight_g": 290000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 560 mm shaft, SKF lists NU20-560-ECMA as single-row caged cylindrical roller: 820 mm OD, 150 mm wide, Pu 560 kN, the catalogue lists 630 r/min thermal reference speed and 1,000 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. With C 3800 kN and C0 7650 kN, size the bearing on the 560×820 mm ISO 15 envelope and check the 560 kN Pu against the equivalent-load floor; the catalogue lists 630 r/min thermal reference speed and 1,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 560 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/560, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/560 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 820 mm raceway.",
      "The 3800/7650 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-560-ECMA?",
        "a": "SKF NU 20/560 ECMA is a single-row caged cylindrical roller bearing with 560 mm bore, 820 mm OD and 150 mm width per ISO 15. SKF lists C 3800 kN, C0 7650 kN, Pu 560 kN, reference speed 630 r/min and limiting speed 1,000 r/min, mass about 290000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-560-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-560-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-560-ECMA",
      "SKF NU 20/560 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-600-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/600 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 600,
    "D_mm": 870,
    "B_mm": 155,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 4180,
    "static_load_kN": 8000,
    "fatigue_load_limit_kN": 570,
    "max_rpm": 900,
    "reference_speed_rpm": 600,
    "limiting_speed_rpm": 900,
    "weight_g": 325000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 20/600 ECMA is a single-row caged cylindrical roller bearing sized 600×870×155 mm — a dimension series 20 (light section for large shafts), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 135.0 mm and the catalogue mass 325000 g; at 4180 kN dynamic rating this is roughly 6.97 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/600, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/600 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 155 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 4180/8000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-600-ECMA?",
        "a": "SKF NU 20/600 ECMA is a single-row caged cylindrical roller bearing with 600 mm bore, 870 mm OD and 155 mm width per ISO 15. SKF lists C 4180 kN, C0 8000 kN, Pu 570 kN, reference speed 600 r/min and limiting speed 900 r/min, mass about 325000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-600-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-600-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-600-ECMA",
      "SKF NU 20/600 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-630-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/630 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 630,
    "D_mm": 920,
    "B_mm": 170,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 4730,
    "static_load_kN": 9500,
    "fatigue_load_limit_kN": 670,
    "max_rpm": 850,
    "reference_speed_rpm": 560,
    "limiting_speed_rpm": 850,
    "weight_g": 400000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 20/630 ECMA denotes a single-row caged cylindrical roller bearing on the ISO 15 630×920×170 mm envelope, dimension series 20 (light section for large shafts), with catalogue mass 400000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 145.0 mm and the catalogue mass 400000 g; at 4730 kN dynamic rating this is roughly 7.51 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 630 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/630, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/630 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 170 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 920 mm raceway.",
      "The 4730/9500 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-630-ECMA?",
        "a": "SKF NU 20/630 ECMA is a single-row caged cylindrical roller bearing with 630 mm bore, 920 mm OD and 170 mm width per ISO 15. SKF lists C 4730 kN, C0 9500 kN, Pu 670 kN, reference speed 560 r/min and limiting speed 850 r/min, mass about 400000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-630-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-630-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-630-ECMA",
      "SKF NU 20/630 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-710-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/710 ECMA/HB1",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 710,
    "D_mm": 1030,
    "B_mm": 185,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5940,
    "static_load_kN": 12000,
    "fatigue_load_limit_kN": 815,
    "max_rpm": 700,
    "reference_speed_rpm": 480,
    "limiting_speed_rpm": 700,
    "weight_g": 540000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 710 mm shaft, SKF lists NU20-710-ECMA-HB1 as single-row caged cylindrical roller: 1030 mm OD, 185 mm wide, Pu 815 kN, the catalogue lists 480 r/min thermal reference speed and 700 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA/HB1: the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 710 mm seat is about 8.37 kN/mm, typical of dimension series 20 (light section for large shafts); use C0 12000 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 710 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/710, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/710 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5940/12000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-710-ECMA-HB1?",
        "a": "SKF NU 20/710 ECMA/HB1 is a single-row caged cylindrical roller bearing with 710 mm bore, 1030 mm OD and 185 mm width per ISO 15. SKF lists C 5940 kN, C0 12000 kN, Pu 815 kN, reference speed 480 r/min and limiting speed 700 r/min, mass about 540000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-710-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-710-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-710-ECMA-HB1",
      "SKF NU 20/710 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-750-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/750 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 750,
    "D_mm": 1090,
    "B_mm": 195,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 7040,
    "static_load_kN": 14600,
    "fatigue_load_limit_kN": 980,
    "max_rpm": 670,
    "reference_speed_rpm": 430,
    "limiting_speed_rpm": 670,
    "weight_g": 635000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 20/750 ECMA resolves to a 750×1090×195 mm single-row caged cylindrical roller bearing (dimension series 20 (light section for large shafts)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 2.07 (14600 against 7040 kN), and the Pu figure 980 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 430 r/min thermal reference speed and 670 r/min mechanical limiting speed. Fit practice for NU20-750-ECMA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/750, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/750 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 195 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 1090 mm raceway.",
      "The 7040/14600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-750-ECMA?",
        "a": "SKF NU 20/750 ECMA is a single-row caged cylindrical roller bearing with 750 mm bore, 1090 mm OD and 195 mm width per ISO 15. SKF lists C 7040 kN, C0 14600 kN, Pu 980 kN, reference speed 430 r/min and limiting speed 670 r/min, mass about 635000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-750-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-750-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-750-ECMA",
      "SKF NU 20/750 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-800-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/800 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 800,
    "D_mm": 1150,
    "B_mm": 200,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 7040,
    "static_load_kN": 14600,
    "fatigue_load_limit_kN": 950,
    "max_rpm": 630,
    "reference_speed_rpm": 400,
    "limiting_speed_rpm": 630,
    "weight_g": 715000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 20/800 ECMA denotes a single-row caged cylindrical roller bearing on the ISO 15 800×1150×200 mm envelope, dimension series 20 (light section for large shafts), with catalogue mass 715000 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 175.0 mm and the catalogue mass 715000 g; at 7040 kN dynamic rating this is roughly 8.80 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/800, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/800 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 1150 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 1150 mm raceway.",
      "The 7040/14600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-800-ECMA?",
        "a": "SKF NU 20/800 ECMA is a single-row caged cylindrical roller bearing with 800 mm bore, 1150 mm OD and 200 mm width per ISO 15. SKF lists C 7040 kN, C0 14600 kN, Pu 950 kN, reference speed 400 r/min and limiting speed 630 r/min, mass about 715000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-800-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-800-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-800-ECMA",
      "SKF NU 20/800 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU20-850-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 20/850 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 850,
    "D_mm": 1220,
    "B_mm": 212,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 8420,
    "static_load_kN": 18600,
    "fatigue_load_limit_kN": 1200,
    "max_rpm": 560,
    "reference_speed_rpm": 360,
    "limiting_speed_rpm": 560,
    "weight_g": 880000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 850 mm shaft, SKF lists NU20-850-ECMA as single-row caged cylindrical roller: 1220 mm OD, 212 mm wide, Pu 1200 kN, the catalogue lists 360 r/min thermal reference speed and 560 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 2.21 (18600 against 8420 kN), and the Pu figure 1200 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 360 r/min thermal reference speed and 560 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 20/850, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 20/850 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 1220 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 1220 mm raceway.",
      "The 8420/18600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU20-850-ECMA?",
        "a": "SKF NU 20/850 ECMA is a single-row caged cylindrical roller bearing with 850 mm bore, 1220 mm OD and 212 mm width per ISO 15. SKF lists C 8420 kN, C0 18600 kN, Pu 1200 kN, reference speed 360 r/min and limiting speed 560 r/min, mass about 880000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU20-850-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU20-850-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU20-850-ECMA",
      "SKF NU 20/850 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU202-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 202 ECP",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 12.5,
    "static_load_kN": 10.2,
    "fatigue_load_limit_kN": 1.22,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 47,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 15 mm shaft, SKF lists NU202-ECP as single-row caged cylindrical roller: 35 mm OD, 11 mm wide, Pu 1.22 kN, the catalogue lists 22,000 r/min thermal reference speed and 26,000 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 15 mm seat is about 0.83 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 10.2 kN for static checks such as crane hook blocks standing under load. Fit practice for NU202-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "small pump rotor shafts",
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 202, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 202 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 35 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 35 mm raceway.",
      "The 12.5/10.2 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU202-ECP?",
        "a": "SKF NU 202 ECP is a single-row caged cylindrical roller bearing with 15 mm bore, 35 mm OD and 11 mm width per ISO 15. SKF lists C 12.5 kN, C0 10.2 kN, Pu 1.22 kN, reference speed 22,000 r/min and limiting speed 26,000 r/min, mass about 47 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU202-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU202-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ202-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 15×35×11 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU202-ECP",
      "SKF NU 202 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU203-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 203 ECP",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 20,
    "static_load_kN": 14.3,
    "fatigue_load_limit_kN": 1.73,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 68,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 17 mm shaft, SKF lists NU203-ECP as single-row caged cylindrical roller: 40 mm OD, 12 mm wide, Pu 1.73 kN, the catalogue lists 20,000 r/min thermal reference speed and 22,000 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 0.72 (14.3 against 20 kN), and the Pu figure 1.73 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 20,000 r/min thermal reference speed and 22,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 203, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 203 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 12 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 40 mm raceway.",
      "The 20/14.3 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU203-ECP?",
        "a": "SKF NU 203 ECP is a single-row caged cylindrical roller bearing with 17 mm bore, 40 mm OD and 12 mm width per ISO 15. SKF lists C 20 kN, C0 14.3 kN, Pu 1.73 kN, reference speed 20,000 r/min and limiting speed 22,000 r/min, mass about 68 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU203-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU203-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×12 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×12 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×12 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU203-ECP",
      "SKF NU 203 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2060-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2060 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 300,
    "D_mm": 460,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1510,
    "static_load_kN": 2600,
    "fatigue_load_limit_kN": 245,
    "max_rpm": 2000,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 2000,
    "weight_g": 62000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 300 mm shaft, SKF lists NU2060-ECMA as single-row caged cylindrical roller: 460 mm OD, 95 mm wide, Pu 245 kN, the catalogue lists 1,300 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 80.0 mm and the catalogue mass 62000 g; at 1510 kN dynamic rating this is roughly 5.03 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 2060, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2060 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1510/2600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2060-ECMA?",
        "a": "SKF NU 2060 ECMA is a single-row caged cylindrical roller bearing with 300 mm bore, 460 mm OD and 95 mm width per ISO 15. SKF lists C 1510 kN, C0 2600 kN, Pu 245 kN, reference speed 1,300 r/min and limiting speed 2,000 r/min, mass about 62000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2060-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2060-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2060",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2060-ECMA",
      "SKF NU 2060 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2088-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2088 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 440,
    "D_mm": 650,
    "B_mm": 122,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2550,
    "static_load_kN": 4900,
    "fatigue_load_limit_kN": 390,
    "max_rpm": 1300,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 1300,
    "weight_g": 145000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2088 ECMA is a single-row caged cylindrical roller bearing sized 440×650×122 mm — a dimension series 20 (light section for large shafts), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 105.0 mm and the catalogue mass 145000 g; at 2550 kN dynamic rating this is roughly 5.80 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 440 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 2088, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2088 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 650 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 650 mm raceway.",
      "The 2550/4900 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2088-ECMA?",
        "a": "SKF NU 2088 ECMA is a single-row caged cylindrical roller bearing with 440 mm bore, 650 mm OD and 122 mm width per ISO 15. SKF lists C 2550 kN, C0 4900 kN, Pu 390 kN, reference speed 8,500 r/min and limiting speed 1,300 r/min, mass about 145000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2088-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2088-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2088",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2088-ECMA",
      "SKF NU 2088 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2096-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2096 ECMA",
    "series": "NU2000-series",
    "type": "cylindrical_roller",
    "d_mm": 480,
    "D_mm": 700,
    "B_mm": 128,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2860,
    "static_load_kN": 5600,
    "fatigue_load_limit_kN": 430,
    "max_rpm": 1200,
    "reference_speed_rpm": 750,
    "limiting_speed_rpm": 1200,
    "weight_g": 179000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2096 ECMA resolves to a 480×700×128 mm single-row caged cylindrical roller bearing (dimension series 20 (light section for large shafts)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 110.0 mm and the catalogue mass 179000 g; at 2860 kN dynamic rating this is roughly 5.96 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 480 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 20 (light section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 2096, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2096 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 128 mm-wide ring and concentrates load.",
      "The 2860/5600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2096-ECMA?",
        "a": "SKF NU 2096 ECMA is a single-row caged cylindrical roller bearing with 480 mm bore, 700 mm OD and 128 mm width per ISO 15. SKF lists C 2860 kN, C0 5600 kN, Pu 430 kN, reference speed 750 r/min and limiting speed 1,200 r/min, mass about 179000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2096-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2096-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2096",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2096-ECMA",
      "SKF NU 2096 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU22-560-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 22/560 ECMA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 560,
    "D_mm": 1030,
    "B_mm": 272,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 9900,
    "static_load_kN": 16600,
    "fatigue_load_limit_kN": 1160,
    "max_rpm": 800,
    "reference_speed_rpm": 530,
    "limiting_speed_rpm": 800,
    "weight_g": 1090000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 22/560 ECMA resolves to a 560×1030×272 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 9900 kN and C0 16600 kN, size the bearing on the 560×1030 mm ISO 15 envelope and check the 1160 kN Pu against the equivalent-load floor; the catalogue lists 530 r/min thermal reference speed and 800 r/min mechanical limiting speed. Fit practice for NU22-560-ECMA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 22/560, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 22/560 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 272 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 1030 mm raceway.",
      "The 9900/16600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU22-560-ECMA?",
        "a": "SKF NU 22/560 ECMA is a single-row caged cylindrical roller bearing with 560 mm bore, 1030 mm OD and 272 mm width per ISO 15. SKF lists C 9900 kN, C0 16600 kN, Pu 1160 kN, reference speed 530 r/min and limiting speed 800 r/min, mass about 1090000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU22-560-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU22-560-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU22",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU22-560-ECMA",
      "SKF NU 22/560 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2203-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2203 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 21.6,
    "fatigue_load_limit_kN": 2.65,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 87,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2203-ECP is the 17 mm bore entry in the NU2200 range: a 17×40×16 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 27.5 kN / C0 21.6 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 17 mm seat is about 1.62 kN/mm, typical of dimension series 22 (light-section, wide); use C0 21.6 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2203-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "small pump rotor shafts",
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2203, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2203 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 16 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 40 mm raceway.",
      "The 27.5/21.6 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2203-ECP?",
        "a": "SKF NU 2203 ECP is a single-row caged cylindrical roller bearing with 17 mm bore, 40 mm OD and 16 mm width per ISO 15. SKF lists C 27.5 kN, C0 21.6 kN, Pu 2.65 kN, reference speed 20,000 r/min and limiting speed 22,000 r/min, mass about 87 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2203-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2203-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×16 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×16 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2203-ECP",
      "SKF NU 2203 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2204-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2204 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 34.5,
    "static_load_kN": 27.5,
    "fatigue_load_limit_kN": 3.45,
    "max_rpm": 19000,
    "reference_speed_rpm": 17000,
    "limiting_speed_rpm": 19000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2204-ECP is the 20 mm bore entry in the NU2200 range: a 20×47×18 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 34.5 kN / C0 27.5 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 0.80 (27.5 against 34.5 kN), and the Pu figure 3.45 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 17,000 r/min thermal reference speed and 19,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2204, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2204 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 47 mm raceway.",
      "The 34.5/27.5 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2204-ECP?",
        "a": "SKF NU 2204 ECP is a single-row caged cylindrical roller bearing with 20 mm bore, 47 mm OD and 18 mm width per ISO 15. SKF lists C 34.5 kN, C0 27.5 kN, Pu 3.45 kN, reference speed 17,000 r/min and limiting speed 19,000 r/min, mass about 140 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2204-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2204-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2204-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×47×18 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2204-ECP",
      "SKF NU 2204 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU221-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 221 ECP",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 300,
    "static_load_kN": 315,
    "fatigue_load_limit_kN": 36.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 3950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 221 ECP is a single-row caged cylindrical roller bearing sized 105×190×36 mm — a dimension series 2 (light-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.05 (315 against 300 kN), and the Pu figure 36.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,800 r/min thermal reference speed and 4,300 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 221, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 221 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 190 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 190 mm raceway.",
      "The 300/315 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU221-ECP?",
        "a": "SKF NU 221 ECP is a single-row caged cylindrical roller bearing with 105 mm bore, 190 mm OD and 36 mm width per ISO 15. SKF lists C 300 kN, C0 315 kN, Pu 36.5 kN, reference speed 3,800 r/min and limiting speed 4,300 r/min, mass about 3950 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU221-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU221-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU221",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 105×190×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N221-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×190×36 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ221-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×190×36 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP221-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×190×36 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU221-ECP",
      "SKF NU 221 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2213-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2213 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 170,
    "static_load_kN": 180,
    "fatigue_load_limit_kN": 24,
    "max_rpm": 6700,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 6700,
    "weight_g": 1400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2213 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 65×120×31 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 1400 g. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 27.5 mm and the catalogue mass 1400 g; at 170 kN dynamic rating this is roughly 2.62 kN of C per millimetre of bore before application factors. Fit practice for NU2213-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2213, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2213 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "The 170/180 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2213-ECP?",
        "a": "SKF NU 2213 ECP is a single-row caged cylindrical roller bearing with 65 mm bore, 120 mm OD and 31 mm width per ISO 15. SKF lists C 170 kN, C0 180 kN, Pu 24 kN, reference speed 6,300 r/min and limiting speed 6,700 r/min, mass about 1400 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2213-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2213-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2213",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2213-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2213-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×31 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2213-ECP",
      "SKF NU 2213 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2214-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2214 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 180,
    "static_load_kN": 193,
    "fatigue_load_limit_kN": 25.5,
    "max_rpm": 6300,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6300,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2214 ECP resolves to a 70×125×31 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 180 kN and C0 193 kN, size the bearing on the 70×125 mm ISO 15 envelope and check the 25.5 kN Pu against the equivalent-load floor; the catalogue lists 6,000 r/min thermal reference speed and 6,300 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 70 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2214, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2214 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 125 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "The 180/193 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2214-ECP?",
        "a": "SKF NU 2214 ECP is a single-row caged cylindrical roller bearing with 70 mm bore, 125 mm OD and 31 mm width per ISO 15. SKF lists C 180 kN, C0 193 kN, Pu 25.5 kN, reference speed 6,000 r/min and limiting speed 6,300 r/min, mass about 1500 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2214-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2214-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2214",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2214-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2214-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×31 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2214-ECP",
      "SKF NU 2214 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2215-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2215 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 186,
    "static_load_kN": 208,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 6000,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6000,
    "weight_g": 1600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2215-ECP is the 75 mm bore entry in the NU2200 range: a 75×130×31 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 186 kN / C0 208 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 186 kN and C0 208 kN, size the bearing on the 75×130 mm ISO 15 envelope and check the 27 kN Pu against the equivalent-load floor; the catalogue lists 5,600 r/min thermal reference speed and 6,000 r/min mechanical limiting speed. Fit practice for NU2215-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2215, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2215 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 186/208 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2215-ECP?",
        "a": "SKF NU 2215 ECP is a single-row caged cylindrical roller bearing with 75 mm bore, 130 mm OD and 31 mm width per ISO 15. SKF lists C 186 kN, C0 208 kN, Pu 27 kN, reference speed 5,600 r/min and limiting speed 6,000 r/min, mass about 1600 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2215-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2215-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2215",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2215-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2215-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×31 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2215-ECP",
      "SKF NU 2215 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2216-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2216 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 212,
    "static_load_kN": 245,
    "fatigue_load_limit_kN": 31,
    "max_rpm": 5600,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 5600,
    "weight_g": 1950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2216-ECP is the 80 mm bore entry in the NU2200 range: a 80×140×33 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 212 kN / C0 245 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NU2216-ECP: the catalogue lists 5,300 r/min thermal reference speed and 5,600 r/min mechanical limiting speed. The mass entry 1950 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2216, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2216 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 212/245 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2216-ECP?",
        "a": "SKF NU 2216 ECP is a single-row caged cylindrical roller bearing with 80 mm bore, 140 mm OD and 33 mm width per ISO 15. SKF lists C 212 kN, C0 245 kN, Pu 31 kN, reference speed 5,300 r/min and limiting speed 5,600 r/min, mass about 1950 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2216-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2216-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2216",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2216-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×33 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2216-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×33 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2216-ECP",
      "SKF NU 2216 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2217-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2217 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 250,
    "static_load_kN": 280,
    "fatigue_load_limit_kN": 34.5,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 2500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 85 mm shaft, SKF lists NU2217-ECP as single-row caged cylindrical roller: 150 mm OD, 36 mm wide, Pu 34.5 kN, the catalogue lists 4,800 r/min thermal reference speed and 5,300 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Load-per-bore for the 85 mm seat is about 2.94 kN/mm, typical of dimension series 22 (light-section, wide); use C0 280 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2217-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2217, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2217 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 150 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 250/280 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2217-ECP?",
        "a": "SKF NU 2217 ECP is a single-row caged cylindrical roller bearing with 85 mm bore, 150 mm OD and 36 mm width per ISO 15. SKF lists C 250 kN, C0 280 kN, Pu 34.5 kN, reference speed 4,800 r/min and limiting speed 5,300 r/min, mass about 2500 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2217-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2217-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2217",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×150×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2217-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×36 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2217-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×36 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2217-ECP",
      "SKF NU 2217 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2218-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2218 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 280,
    "static_load_kN": 315,
    "fatigue_load_limit_kN": 39,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 3150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2218 ECP is a single-row caged cylindrical roller bearing sized 90×160×40 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.13 (315 against 280 kN), and the Pu figure 39 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 4,500 r/min thermal reference speed and 5,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 90 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2218, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2218 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 40 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 280/315 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2218-ECP?",
        "a": "SKF NU 2218 ECP is a single-row caged cylindrical roller bearing with 90 mm bore, 160 mm OD and 40 mm width per ISO 15. SKF lists C 280 kN, C0 315 kN, Pu 39 kN, reference speed 4,500 r/min and limiting speed 5,000 r/min, mass about 3150 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2218-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2218-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2218",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 90×160×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2218-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2218-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×40 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2218-ECP",
      "SKF NU 2218 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2219-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2219 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 325,
    "static_load_kN": 375,
    "fatigue_load_limit_kN": 45.5,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 3800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2219 ECP is a single-row caged cylindrical roller bearing sized 95×170×43 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 325 kN and C0 375 kN, size the bearing on the 95×170 mm ISO 15 envelope and check the 45.5 kN Pu against the equivalent-load floor; the catalogue lists 4,300 r/min thermal reference speed and 4,800 r/min mechanical limiting speed. Fit practice for NU2219-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2219, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2219 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 170 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 325/375 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2219-ECP?",
        "a": "SKF NU 2219 ECP is a single-row caged cylindrical roller bearing with 95 mm bore, 170 mm OD and 43 mm width per ISO 15. SKF lists C 325 kN, C0 375 kN, Pu 45.5 kN, reference speed 4,300 r/min and limiting speed 4,800 r/min, mass about 3800 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2219-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2219-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2219",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 95×170×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2219-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×43 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2219-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×43 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2219-ECP",
      "SKF NU 2219 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU222-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 222 ECP",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 335,
    "static_load_kN": 365,
    "fatigue_load_limit_kN": 42.5,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 4700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 222 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 110×200×38 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 4700 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 45.0 mm and the catalogue mass 4700 g; at 335 kN dynamic rating this is roughly 3.05 kN of C per millimetre of bore before application factors. Fit practice for NU222-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 222, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 222 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 38 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 335/365 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU222-ECP?",
        "a": "SKF NU 222 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 200 mm OD and 38 mm width per ISO 15. SKF lists C 335 kN, C0 365 kN, Pu 42.5 kN, reference speed 3,600 r/min and limiting speed 4,000 r/min, mass about 4700 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU222-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU222-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU222",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×38 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×38 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×38 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU222-ECP",
      "SKF NU 222 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2220-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2220 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 380,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 54,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 4750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2220-ECP is the 100 mm bore entry in the NU2200 range: a 100×180×46 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 380 kN / C0 450 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Speed planning for NU2220-ECP: the catalogue lists 4,000 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. The mass entry 4750 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2220, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2220 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "The 380/450 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2220-ECP?",
        "a": "SKF NU 2220 ECP is a single-row caged cylindrical roller bearing with 100 mm bore, 180 mm OD and 46 mm width per ISO 15. SKF lists C 380 kN, C0 450 kN, Pu 54 kN, reference speed 4,000 r/min and limiting speed 4,500 r/min, mass about 4750 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2220-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2220-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2220",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 100×180×46 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2220-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×46 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2220-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×46 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2220-ECP",
      "SKF NU 2220 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2222-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2222 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 440,
    "static_load_kN": 520,
    "fatigue_load_limit_kN": 61,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 6700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2222 ECP is a single-row caged cylindrical roller bearing sized 110×200×53 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.18 (520 against 440 kN), and the Pu figure 61 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,600 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 110 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2222, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2222 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 53 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 440/520 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2222-ECP?",
        "a": "SKF NU 2222 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 200 mm OD and 53 mm width per ISO 15. SKF lists C 440 kN, C0 520 kN, Pu 61 kN, reference speed 3,600 r/min and limiting speed 4,000 r/min, mass about 6700 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2222-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2222-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2222",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×200×53 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×53 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×53 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2222-ECP",
      "SKF NU 2222 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2224-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2224 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 520,
    "static_load_kN": 630,
    "fatigue_load_limit_kN": 72,
    "max_rpm": 3600,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3600,
    "weight_g": 8200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2224 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 120×215×58 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 8200 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 520 kN and C0 630 kN, size the bearing on the 120×215 mm ISO 15 envelope and check the 72 kN Pu against the equivalent-load floor; the catalogue lists 3,400 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 120 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2224, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2224 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "The 520/630 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2224-ECP?",
        "a": "SKF NU 2224 ECP is a single-row caged cylindrical roller bearing with 120 mm bore, 215 mm OD and 58 mm width per ISO 15. SKF lists C 520 kN, C0 630 kN, Pu 72 kN, reference speed 3,400 r/min and limiting speed 3,600 r/min, mass about 8200 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2224-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2224-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2224",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×215×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2224-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×58 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2224-ECP",
      "SKF NU 2224 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2226-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2226 ECP",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 610,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 83,
    "max_rpm": 3400,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3400,
    "weight_g": 10000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2226 ECP resolves to a 130×230×64 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.20 (735 against 610 kN), and the Pu figure 83 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,200 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 130 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2226, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2226 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 230 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 230 mm raceway.",
      "The 610/735 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2226-ECP?",
        "a": "SKF NU 2226 ECP is a single-row caged cylindrical roller bearing with 130 mm bore, 230 mm OD and 64 mm width per ISO 15. SKF lists C 610 kN, C0 735 kN, Pu 83 kN, reference speed 3,200 r/min and limiting speed 3,400 r/min, mass about 10000 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2226-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2226-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2226",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×230×64 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2226-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×64 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×64 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2226-ECP",
      "SKF NU 2226 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2228-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2228 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 655,
    "static_load_kN": 830,
    "fatigue_load_limit_kN": 93,
    "max_rpm": 4800,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 4800,
    "weight_g": 15000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2228 ECML resolves to a 140×250×68 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 55.0 mm and the catalogue mass 15000 g; at 655 kN dynamic rating this is roughly 4.68 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 140 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2228, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2228 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 68 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 68 mm-wide ring and concentrates load.",
      "The 655/830 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2228-ECML?",
        "a": "SKF NU 2228 ECML is a single-row caged cylindrical roller bearing with 140 mm bore, 250 mm OD and 68 mm width per ISO 15. SKF lists C 655 kN, C0 830 kN, Pu 93 kN, reference speed 2,800 r/min and limiting speed 4,800 r/min, mass about 15000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2228-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2228-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2228",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×250×68 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2228-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×68 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2228-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×68 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2228-ECML",
      "SKF NU 2228 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2230-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2230 ECM",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 735,
    "static_load_kN": 930,
    "fatigue_load_limit_kN": 100,
    "max_rpm": 2800,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 2800,
    "weight_g": 18500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2230-ECM is the 150 mm bore entry in the NU2200 range: a 150×270×73 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 735 kN / C0 930 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Speed planning for NU2230-ECM: the catalogue lists 2,600 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. The mass entry 18500 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2230, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2230 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 735/930 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2230-ECM?",
        "a": "SKF NU 2230 ECM is a single-row caged cylindrical roller bearing with 150 mm bore, 270 mm OD and 73 mm width per ISO 15. SKF lists C 735 kN, C0 930 kN, Pu 100 kN, reference speed 2,600 r/min and limiting speed 2,800 r/min, mass about 18500 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2230-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2230-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2230",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 150×270×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2230-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×270×73 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2230-ECM",
      "SKF NU 2230 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2232-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2232 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 930,
    "static_load_kN": 1200,
    "fatigue_load_limit_kN": 129,
    "max_rpm": 4000,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 4000,
    "weight_g": 23000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 160 mm shaft, SKF lists NU2232-ECML as single-row caged cylindrical roller: 290 mm OD, 80 mm wide, Pu 129 kN, the catalogue lists 2,400 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. With C 930 kN and C0 1200 kN, size the bearing on the 160×290 mm ISO 15 envelope and check the 129 kN Pu against the equivalent-load floor; the catalogue lists 2,400 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2232, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2232 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 930/1200 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2232-ECML?",
        "a": "SKF NU 2232 ECML is a single-row caged cylindrical roller bearing with 160 mm bore, 290 mm OD and 80 mm width per ISO 15. SKF lists C 930 kN, C0 1200 kN, Pu 129 kN, reference speed 2,400 r/min and limiting speed 4,000 r/min, mass about 23000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2232-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2232-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2232",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 160×290×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2232-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×290×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2232-ECML",
      "SKF NU 2232 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2234-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2234 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1060,
    "static_load_kN": 1340,
    "fatigue_load_limit_kN": 140,
    "max_rpm": 3800,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 3800,
    "weight_g": 28000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2234 ECML denotes a single-row caged cylindrical roller bearing on the ISO 15 170×310×86 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 28000 g. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Load-per-bore for the 170 mm seat is about 6.24 kN/mm, typical of dimension series 22 (light-section, wide); use C0 1340 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2234, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2234 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1060/1340 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2234-ECML?",
        "a": "SKF NU 2234 ECML is a single-row caged cylindrical roller bearing with 170 mm bore, 310 mm OD and 86 mm width per ISO 15. SKF lists C 1060 kN, C0 1340 kN, Pu 140 kN, reference speed 2,200 r/min and limiting speed 3,800 r/min, mass about 28000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2234-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2234-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2234",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 170×310×86 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2234-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 170×310×86 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2234-ECML",
      "SKF NU 2234 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2236-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2236 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1100,
    "static_load_kN": 1430,
    "fatigue_load_limit_kN": 146,
    "max_rpm": 3600,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 3600,
    "weight_g": 30000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 180 mm shaft, SKF lists NU2236-ECML as single-row caged cylindrical roller: 320 mm OD, 86 mm wide, Pu 146 kN, the catalogue lists 2,200 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. The radial section height is 70.0 mm and the catalogue mass 30000 g; at 1100 kN dynamic rating this is roughly 6.11 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 180 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2236, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2236 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 320 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1100/1430 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2236-ECML?",
        "a": "SKF NU 2236 ECML is a single-row caged cylindrical roller bearing with 180 mm bore, 320 mm OD and 86 mm width per ISO 15. SKF lists C 1100 kN, C0 1430 kN, Pu 146 kN, reference speed 2,200 r/min and limiting speed 3,600 r/min, mass about 30000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2236-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2236-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2236",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 180×320×86 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2236-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×320×86 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2236-ECML",
      "SKF NU 2236 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2238-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2238 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1220,
    "static_load_kN": 1600,
    "fatigue_load_limit_kN": 160,
    "max_rpm": 3400,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 3400,
    "weight_g": 35500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2238 ECML denotes a single-row caged cylindrical roller bearing on the ISO 15 190×340×92 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 35500 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Speed planning for NU2238-ECML: the catalogue lists 2,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. The mass entry 35500 g covers the complete catalogue execution. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 190 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2238, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2238 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 92 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1220/1600 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2238-ECML?",
        "a": "SKF NU 2238 ECML is a single-row caged cylindrical roller bearing with 190 mm bore, 340 mm OD and 92 mm width per ISO 15. SKF lists C 1220 kN, C0 1600 kN, Pu 160 kN, reference speed 2,000 r/min and limiting speed 3,400 r/min, mass about 35500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2238-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2238-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2238",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 190×340×92 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2238-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×340×92 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2238-ECML",
      "SKF NU 2238 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU224-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 224 ECP",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 390,
    "static_load_kN": 430,
    "fatigue_load_limit_kN": 49,
    "max_rpm": 3600,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3600,
    "weight_g": 5750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 224 ECP resolves to a 120×215×40 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NU224-ECP: the catalogue lists 3,400 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. The mass entry 5750 g covers the complete catalogue execution. Fit practice for NU224-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 224, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 224 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "The 390/430 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU224-ECP?",
        "a": "SKF NU 224 ECP is a single-row caged cylindrical roller bearing with 120 mm bore, 215 mm OD and 40 mm width per ISO 15. SKF lists C 390 kN, C0 430 kN, Pu 49 kN, reference speed 3,400 r/min and limiting speed 3,600 r/min, mass about 5750 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU224-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU224-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU224",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×215×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×40 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP224-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×40 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU224-ECP",
      "SKF NU 224 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2240-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2240 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 98,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1370,
    "static_load_kN": 1800,
    "fatigue_load_limit_kN": 180,
    "max_rpm": 3200,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 3200,
    "weight_g": 44000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2240 ECML is a single-row caged cylindrical roller bearing sized 200×360×98 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1370 kN and C0 1800 kN, size the bearing on the 200×360 mm ISO 15 envelope and check the 180 kN Pu against the equivalent-load floor; the catalogue lists 1,900 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. Fit practice for NU2240-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2240, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2240 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 360 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 360 mm raceway.",
      "The 1370/1800 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2240-ECML?",
        "a": "SKF NU 2240 ECML is a single-row caged cylindrical roller bearing with 200 mm bore, 360 mm OD and 98 mm width per ISO 15. SKF lists C 1370 kN, C0 1800 kN, Pu 180 kN, reference speed 1,900 r/min and limiting speed 3,200 r/min, mass about 44000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2240-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2240-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2240",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 200×360×98 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2240-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×360×98 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2240-ECML",
      "SKF NU 2240 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2244-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2244 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 400,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1570,
    "static_load_kN": 2280,
    "fatigue_load_limit_kN": 212,
    "max_rpm": 3000,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 3000,
    "weight_g": 58000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2244 ECML is a single-row caged cylindrical roller bearing sized 220×400×108 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 90.0 mm and the catalogue mass 58000 g; at 1570 kN dynamic rating this is roughly 7.14 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2244, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2244 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 1570/2280 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2244-ECML?",
        "a": "SKF NU 2244 ECML is a single-row caged cylindrical roller bearing with 220 mm bore, 400 mm OD and 108 mm width per ISO 15. SKF lists C 1570 kN, C0 2280 kN, Pu 212 kN, reference speed 1,600 r/min and limiting speed 3,000 r/min, mass about 58000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2244-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2244-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2244",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 220×400×108 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2244-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×108 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2244-ECML",
      "SKF NU 2244 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2248-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2248 MA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1450,
    "static_load_kN": 2360,
    "fatigue_load_limit_kN": 216,
    "max_rpm": 2200,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 2200,
    "weight_g": 84000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 240 mm shaft, SKF lists NU2248-MA as single-row caged cylindrical roller: 440 mm OD, 120 mm wide, Pu 216 kN, the catalogue lists 1,500 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. With C 1450 kN and C0 2360 kN, size the bearing on the 240×440 mm ISO 15 envelope and check the 216 kN Pu against the equivalent-load floor; the catalogue lists 1,500 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 240 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2248, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2248 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 120 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1450/2360 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2248-MA?",
        "a": "SKF NU 2248 MA is a single-row caged cylindrical roller bearing with 240 mm bore, 440 mm OD and 120 mm width per ISO 15. SKF lists C 1450 kN, C0 2360 kN, Pu 216 kN, reference speed 1,500 r/min and limiting speed 2,200 r/min, mass about 84000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2248-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2248-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2248",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ2248-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 240×440×120 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2248-MA",
      "SKF NU 2248 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2252-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2252 MA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 260,
    "D_mm": 480,
    "B_mm": 130,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1790,
    "static_load_kN": 3000,
    "fatigue_load_limit_kN": 265,
    "max_rpm": 2000,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 2000,
    "weight_g": 110000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 260 mm shaft, SKF lists NU2252-MA as single-row caged cylindrical roller: 480 mm OD, 130 mm wide, Pu 265 kN, the catalogue lists 1,400 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Load-per-bore for the 260 mm seat is about 6.88 kN/mm, typical of dimension series 22 (light-section, wide); use C0 3000 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2252, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2252 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 480 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1790/3000 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2252-MA?",
        "a": "SKF NU 2252 MA is a single-row caged cylindrical roller bearing with 260 mm bore, 480 mm OD and 130 mm width per ISO 15. SKF lists C 1790 kN, C0 3000 kN, Pu 265 kN, reference speed 1,400 r/min and limiting speed 2,000 r/min, mass about 110000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2252-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2252-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2252",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ2252-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 260×480×130 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2252-MA",
      "SKF NU 2252 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2256-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2256 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 280,
    "D_mm": 500,
    "B_mm": 130,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2330,
    "static_load_kN": 3750,
    "fatigue_load_limit_kN": 320,
    "max_rpm": 2200,
    "reference_speed_rpm": 1200,
    "limiting_speed_rpm": 2200,
    "weight_g": 115000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2256 ECML denotes a single-row caged cylindrical roller bearing on the ISO 15 280×500×130 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 115000 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 280 mm seat is about 8.32 kN/mm, typical of dimension series 22 (light-section, wide); use C0 3750 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2256-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2256, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2256 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 500 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 2330/3750 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2256-ECML?",
        "a": "SKF NU 2256 ECML is a single-row caged cylindrical roller bearing with 280 mm bore, 500 mm OD and 130 mm width per ISO 15. SKF lists C 2330 kN, C0 3750 kN, Pu 320 kN, reference speed 1,200 r/min and limiting speed 2,200 r/min, mass about 115000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2256-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2256-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2256",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 280×500×130 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU2256",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2256-ECML",
      "SKF NU 2256 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU226-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 226 ECP",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 415,
    "static_load_kN": 455,
    "fatigue_load_limit_kN": 51,
    "max_rpm": 3400,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3400,
    "weight_g": 6450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU226-ECP is the 130 mm bore entry in the NU200 range: a 130×230×40 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 415 kN / C0 455 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.10 (455 against 415 kN), and the Pu figure 51 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,200 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Fit practice for NU226-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 226, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 226 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 230 mm raceway.",
      "The 415/455 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU226-ECP?",
        "a": "SKF NU 226 ECP is a single-row caged cylindrical roller bearing with 130 mm bore, 230 mm OD and 40 mm width per ISO 15. SKF lists C 415 kN, C0 455 kN, Pu 51 kN, reference speed 3,200 r/min and limiting speed 3,400 r/min, mass about 6450 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU226-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU226-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU226",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×230×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×40 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP226-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×40 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU226-ECP",
      "SKF NU 226 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2260-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2260 MA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 300,
    "D_mm": 540,
    "B_mm": 140,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2090,
    "static_load_kN": 3450,
    "fatigue_load_limit_kN": 300,
    "max_rpm": 1800,
    "reference_speed_rpm": 1200,
    "limiting_speed_rpm": 1800,
    "weight_g": 145000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2260 MA resolves to a 300×540×140 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 120.0 mm and the catalogue mass 145000 g; at 2090 kN dynamic rating this is roughly 6.97 kN of C per millimetre of bore before application factors. Fit practice for NU2260-MA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2260, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2260 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 140 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 540 mm raceway.",
      "The 2090/3450 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2260-MA?",
        "a": "SKF NU 2260 MA is a single-row caged cylindrical roller bearing with 300 mm bore, 540 mm OD and 140 mm width per ISO 15. SKF lists C 2090 kN, C0 3450 kN, Pu 300 kN, reference speed 1,200 r/min and limiting speed 1,800 r/min, mass about 145000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2260-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2260-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2260",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 300×540×140 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU2260",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2260-MA",
      "SKF NU 2260 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2264-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2264 ECML",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 320,
    "D_mm": 580,
    "B_mm": 150,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3190,
    "static_load_kN": 5000,
    "fatigue_load_limit_kN": 415,
    "max_rpm": 1900,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1900,
    "weight_g": 176000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2264 ECML resolves to a 320×580×150 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Load-per-bore for the 320 mm seat is about 9.97 kN/mm, typical of dimension series 22 (light-section, wide); use C0 5000 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 320 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2264, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2264 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 580 mm raceway.",
      "The 3190/5000 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2264-ECML?",
        "a": "SKF NU 2264 ECML is a single-row caged cylindrical roller bearing with 320 mm bore, 580 mm OD and 150 mm width per ISO 15. SKF lists C 3190 kN, C0 5000 kN, Pu 415 kN, reference speed 1,000 r/min and limiting speed 1,900 r/min, mass about 176000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2264-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2264-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2264",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 320×580×150 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU2264",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2264-ECML",
      "SKF NU 2264 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2268-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2268 MA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 340,
    "D_mm": 620,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2640,
    "static_load_kN": 4500,
    "fatigue_load_limit_kN": 365,
    "max_rpm": 1500,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1500,
    "weight_g": 226000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2268 MA is a single-row caged cylindrical roller bearing sized 340×620×165 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. Load-per-bore for the 340 mm seat is about 7.76 kN/mm, typical of dimension series 22 (light-section, wide); use C0 4500 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 340 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2268, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2268 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 620 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 2640/4500 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2268-MA?",
        "a": "SKF NU 2268 MA is a single-row caged cylindrical roller bearing with 340 mm bore, 620 mm OD and 165 mm width per ISO 15. SKF lists C 2640 kN, C0 4500 kN, Pu 365 kN, reference speed 1,000 r/min and limiting speed 1,500 r/min, mass about 226000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2268-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2268-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2268",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2268-MA",
      "SKF NU 2268 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2272-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2272 MA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 360,
    "D_mm": 650,
    "B_mm": 170,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2920,
    "static_load_kN": 4900,
    "fatigue_load_limit_kN": 400,
    "max_rpm": 1400,
    "reference_speed_rpm": 950,
    "limiting_speed_rpm": 1400,
    "weight_g": 257000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2272 MA is a single-row caged cylindrical roller bearing sized 360×650×170 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The radial section height is 145.0 mm and the catalogue mass 257000 g; at 2920 kN dynamic rating this is roughly 8.11 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2272, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2272 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 2920/4900 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2272-MA?",
        "a": "SKF NU 2272 MA is a single-row caged cylindrical roller bearing with 360 mm bore, 650 mm OD and 170 mm width per ISO 15. SKF lists C 2920 kN, C0 4900 kN, Pu 400 kN, reference speed 950 r/min and limiting speed 1,400 r/min, mass about 257000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2272-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2272-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2272",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2272-MA",
      "SKF NU 2272 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2276-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2276 ECMA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 380,
    "D_mm": 680,
    "B_mm": 175,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3960,
    "static_load_kN": 6400,
    "fatigue_load_limit_kN": 510,
    "max_rpm": 1300,
    "reference_speed_rpm": 850,
    "limiting_speed_rpm": 1300,
    "weight_g": 288000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2276 ECMA is a single-row caged cylindrical roller bearing sized 380×680×175 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Speed planning for NU2276-ECMA: the catalogue lists 850 r/min thermal reference speed and 1,300 r/min mechanical limiting speed. The mass entry 288000 g covers the complete catalogue execution. Fit practice for NU2276-ECMA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2276, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2276 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 175 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 3960/6400 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2276-ECMA?",
        "a": "SKF NU 2276 ECMA is a single-row caged cylindrical roller bearing with 380 mm bore, 680 mm OD and 175 mm width per ISO 15. SKF lists C 3960 kN, C0 6400 kN, Pu 510 kN, reference speed 850 r/min and limiting speed 1,300 r/min, mass about 288000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2276-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2276-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2276",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2276-ECMA",
      "SKF NU 2276 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU228-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 228 ECM",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 450,
    "static_load_kN": 510,
    "fatigue_load_limit_kN": 57,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 9400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 228 ECM denotes a single-row caged cylindrical roller bearing on the ISO 15 140×250×42 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 9400 g. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Speed planning for NU228-ECM: the catalogue lists 2,800 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. The mass entry 9400 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 228, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 228 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 250 mm raceway.",
      "The 450/510 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU228-ECM?",
        "a": "SKF NU 228 ECM is a single-row caged cylindrical roller bearing with 140 mm bore, 250 mm OD and 42 mm width per ISO 15. SKF lists C 450 kN, C0 510 kN, Pu 57 kN, reference speed 2,800 r/min and limiting speed 3,200 r/min, mass about 9400 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU228-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU228-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU228",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×250×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ228-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×42 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP228-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×42 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU228-ECM",
      "SKF NU 228 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2292-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2292 MA",
    "series": "NU2200-series",
    "type": "cylindrical_roller",
    "d_mm": 460,
    "D_mm": 830,
    "B_mm": 212,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5120,
    "static_load_kN": 8650,
    "fatigue_load_limit_kN": 655,
    "max_rpm": 1100,
    "reference_speed_rpm": 700,
    "limiting_speed_rpm": 1100,
    "weight_g": 527000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2292 MA denotes a single-row caged cylindrical roller bearing on the ISO 15 460×830×212 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 527000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Speed planning for NU2292-MA: the catalogue lists 700 r/min thermal reference speed and 1,100 r/min mechanical limiting speed. The mass entry 527000 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2292, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2292 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 212 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5120/8650 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2292-MA?",
        "a": "SKF NU 2292 MA is a single-row caged cylindrical roller bearing with 460 mm bore, 830 mm OD and 212 mm width per ISO 15. SKF lists C 5120 kN, C0 8650 kN, Pu 655 kN, reference speed 700 r/min and limiting speed 1,100 r/min, mass about 527000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2292-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2292-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2292",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2292-MA",
      "SKF NU 2292 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU230-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 230 ECM",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 510,
    "static_load_kN": 600,
    "fatigue_load_limit_kN": 64,
    "max_rpm": 2800,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 2800,
    "weight_g": 11500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 230 ECM is a single-row caged cylindrical roller bearing sized 150×270×45 mm — a dimension series 2 (light-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.18 (600 against 510 kN), and the Pu figure 64 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,600 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 230, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 230 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 45 mm-wide ring and concentrates load.",
      "The 510/600 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU230-ECM?",
        "a": "SKF NU 230 ECM is a single-row caged cylindrical roller bearing with 150 mm bore, 270 mm OD and 45 mm width per ISO 15. SKF lists C 510 kN, C0 600 kN, Pu 64 kN, reference speed 2,600 r/min and limiting speed 2,800 r/min, mass about 11500 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU230-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU230-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU230",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 150×270×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ230-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×270×45 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP230-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×270×45 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU230-ECM",
      "SKF NU 230 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2304-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2304 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 47.5,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 18000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 18000,
    "weight_g": 210,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2304 ECP resolves to a 20×52×21 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 47.5 kN and C0 38 kN, size the bearing on the 20×52 mm ISO 15 envelope and check the 4.8 kN Pu against the equivalent-load floor; the catalogue lists 15,000 r/min thermal reference speed and 18,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts",
      "small pump rotor shafts",
      "small industrial electric-motor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2304, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2304 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 21 mm-wide ring and concentrates load.",
      "The 47.5/38 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2304-ECP?",
        "a": "SKF NU 2304 ECP is a single-row caged cylindrical roller bearing with 20 mm bore, 52 mm OD and 21 mm width per ISO 15. SKF lists C 47.5 kN, C0 38 kN, Pu 4.8 kN, reference speed 15,000 r/min and limiting speed 18,000 r/min, mass about 210 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2304-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2304-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2304-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×21 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2304-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×21 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2304-ECP",
      "SKF NU 2304 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2313-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2313 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 285,
    "static_load_kN": 290,
    "fatigue_load_limit_kN": 38,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 3200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2313 ECP is a single-row caged cylindrical roller bearing sized 65×140×48 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 285 kN and C0 290 kN, size the bearing on the 65×140 mm ISO 15 envelope and check the 38 kN Pu against the equivalent-load floor; the catalogue lists 5,300 r/min thermal reference speed and 6,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 65 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2313, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2313 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 140 mm raceway.",
      "The 285/290 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2313-ECP?",
        "a": "SKF NU 2313 ECP is a single-row caged cylindrical roller bearing with 65 mm bore, 140 mm OD and 48 mm width per ISO 15. SKF lists C 285 kN, C0 290 kN, Pu 38 kN, reference speed 5,300 r/min and limiting speed 6,000 r/min, mass about 3200 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2313-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2313-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2313",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 65×140×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2313-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×48 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2313-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×48 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2313-ECP",
      "SKF NU 2313 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2314-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2314 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 315,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 41.5,
    "max_rpm": 5600,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5600,
    "weight_g": 3950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2314 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 70×150×51 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 3950 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Speed planning for NU2314-ECP: the catalogue lists 4,800 r/min thermal reference speed and 5,600 r/min mechanical limiting speed. The mass entry 3950 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2314, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2314 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 150 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 150 mm raceway.",
      "The 315/325 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2314-ECP?",
        "a": "SKF NU 2314 ECP is a single-row caged cylindrical roller bearing with 70 mm bore, 150 mm OD and 51 mm width per ISO 15. SKF lists C 315 kN, C0 325 kN, Pu 41.5 kN, reference speed 4,800 r/min and limiting speed 5,600 r/min, mass about 3950 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2314-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2314-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2314",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 70×150×51 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2314-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×51 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2314-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×51 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2314-ECP",
      "SKF NU 2314 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2315-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2315 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 380,
    "static_load_kN": 400,
    "fatigue_load_limit_kN": 50,
    "max_rpm": 5300,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5300,
    "weight_g": 4800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2315 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 75×160×55 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 4800 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 75 mm seat is about 5.07 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 400 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 75 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2315, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2315 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 55 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 160 mm raceway.",
      "The 380/400 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2315-ECP?",
        "a": "SKF NU 2315 ECP is a single-row caged cylindrical roller bearing with 75 mm bore, 160 mm OD and 55 mm width per ISO 15. SKF lists C 380 kN, C0 400 kN, Pu 50 kN, reference speed 4,500 r/min and limiting speed 5,300 r/min, mass about 4800 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2315-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2315-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2315",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 75×160×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2315-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×55 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2315-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×55 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2315-ECP",
      "SKF NU 2315 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2316-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2316 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 415,
    "static_load_kN": 440,
    "fatigue_load_limit_kN": 55,
    "max_rpm": 5000,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 5000,
    "weight_g": 5750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2316 ECP resolves to a 80×170×58 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.06 (440 against 415 kN), and the Pu figure 55 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 4,300 r/min thermal reference speed and 5,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2316, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2316 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 170 mm raceway.",
      "The 415/440 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2316-ECP?",
        "a": "SKF NU 2316 ECP is a single-row caged cylindrical roller bearing with 80 mm bore, 170 mm OD and 58 mm width per ISO 15. SKF lists C 415 kN, C0 440 kN, Pu 55 kN, reference speed 4,300 r/min and limiting speed 5,000 r/min, mass about 5750 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2316-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2316-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2316",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 80×170×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2316-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2316-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×58 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2316-ECP",
      "SKF NU 2316 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2317-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2317 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 455,
    "static_load_kN": 490,
    "fatigue_load_limit_kN": 60,
    "max_rpm": 4800,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4800,
    "weight_g": 6850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2317-ECP is the 85 mm bore entry in the NU2300 range: a 85×180×60 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 455 kN / C0 490 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 47.5 mm and the catalogue mass 6850 g; at 455 kN dynamic rating this is roughly 5.35 kN of C per millimetre of bore before application factors. Fit practice for NU2317-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2317, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2317 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "The 455/490 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2317-ECP?",
        "a": "SKF NU 2317 ECP is a single-row caged cylindrical roller bearing with 85 mm bore, 180 mm OD and 60 mm width per ISO 15. SKF lists C 455 kN, C0 490 kN, Pu 60 kN, reference speed 4,000 r/min and limiting speed 4,800 r/min, mass about 6850 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2317-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2317-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2317",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×180×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2317-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×60 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2317-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×60 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2317-ECP",
      "SKF NU 2317 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2318-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2318 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 500,
    "static_load_kN": 540,
    "fatigue_load_limit_kN": 65.5,
    "max_rpm": 4500,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4500,
    "weight_g": 8000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2318-ECP is the 90 mm bore entry in the NU2300 range: a 90×190×64 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 500 kN / C0 540 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 500 kN and C0 540 kN, size the bearing on the 90×190 mm ISO 15 envelope and check the 65.5 kN Pu against the equivalent-load floor; the catalogue lists 3,800 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2318, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2318 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 64 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 190 mm raceway.",
      "The 500/540 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2318-ECP?",
        "a": "SKF NU 2318 ECP is a single-row caged cylindrical roller bearing with 90 mm bore, 190 mm OD and 64 mm width per ISO 15. SKF lists C 500 kN, C0 540 kN, Pu 65.5 kN, reference speed 3,800 r/min and limiting speed 4,500 r/min, mass about 8000 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2318-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2318-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2318",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 90×190×64 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2318-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×64 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2318-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×64 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2318-ECP",
      "SKF NU 2318 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2319-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2319 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 530,
    "static_load_kN": 585,
    "fatigue_load_limit_kN": 69.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4300,
    "weight_g": 9350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 95 mm shaft, SKF lists NU2319-ECP as single-row caged cylindrical roller: 200 mm OD, 67 mm wide, Pu 69.5 kN, the catalogue lists 3,600 r/min thermal reference speed and 4,300 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 95 mm seat is about 5.58 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 585 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2319-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2319, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2319 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 530/585 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2319-ECP?",
        "a": "SKF NU 2319 ECP is a single-row caged cylindrical roller bearing with 95 mm bore, 200 mm OD and 67 mm width per ISO 15. SKF lists C 530 kN, C0 585 kN, Pu 69.5 kN, reference speed 3,600 r/min and limiting speed 4,300 r/min, mass about 9350 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2319-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2319-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2319",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 95×200×67 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2319-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×67 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2319-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×67 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2319-ECP",
      "SKF NU 2319 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU232-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 232 ECM",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 585,
    "static_load_kN": 680,
    "fatigue_load_limit_kN": 72,
    "max_rpm": 2600,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2600,
    "weight_g": 14000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 232 ECM denotes a single-row caged cylindrical roller bearing on the ISO 15 160×290×48 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 14000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 585 kN and C0 680 kN, size the bearing on the 160×290 mm ISO 15 envelope and check the 72 kN Pu against the equivalent-load floor; the catalogue lists 2,400 r/min thermal reference speed and 2,600 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 232, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 232 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 48 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 48 mm-wide ring and concentrates load.",
      "The 585/680 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU232-ECM?",
        "a": "SKF NU 232 ECM is a single-row caged cylindrical roller bearing with 160 mm bore, 290 mm OD and 48 mm width per ISO 15. SKF lists C 585 kN, C0 680 kN, Pu 72 kN, reference speed 2,400 r/min and limiting speed 2,600 r/min, mass about 14000 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU232-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU232-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU232",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 160×290×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ232-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×290×48 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP232-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×290×48 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU232-ECM",
      "SKF NU 232 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2320-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2320 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 670,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 85,
    "max_rpm": 3800,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3800,
    "weight_g": 12000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2320 ECP resolves to a 100×215×73 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.10 (735 against 670 kN), and the Pu figure 85 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,200 r/min thermal reference speed and 3,800 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2320, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2320 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 73 mm-wide ring and concentrates load.",
      "The 670/735 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2320-ECP?",
        "a": "SKF NU 2320 ECP is a single-row caged cylindrical roller bearing with 100 mm bore, 215 mm OD and 73 mm width per ISO 15. SKF lists C 670 kN, C0 735 kN, Pu 85 kN, reference speed 3,200 r/min and limiting speed 3,800 r/min, mass about 12000 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2320-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2320-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2320",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 100×215×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2320-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×73 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2320-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×73 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2320-ECP",
      "SKF NU 2320 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2322-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2322 ECP",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 780,
    "static_load_kN": 900,
    "fatigue_load_limit_kN": 102,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 17000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2322-ECP is the 110 mm bore entry in the NU2300 range: a 110×240×80 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 780 kN / C0 900 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 780 kN and C0 900 kN, size the bearing on the 110×240 mm ISO 15 envelope and check the 102 kN Pu against the equivalent-load floor; the catalogue lists 3,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2322, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2322 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 780/900 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2322-ECP?",
        "a": "SKF NU 2322 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 240 mm OD and 80 mm width per ISO 15. SKF lists C 780 kN, C0 900 kN, Pu 102 kN, reference speed 3,000 r/min and limiting speed 3,400 r/min, mass about 17000 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2322-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2322-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2322",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×240×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×80 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2322-ECP",
      "SKF NU 2322 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2324-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2324 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 915,
    "static_load_kN": 1040,
    "fatigue_load_limit_kN": 116,
    "max_rpm": 5000,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 5000,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2324 ECML denotes a single-row caged cylindrical roller bearing on the ISO 15 120×260×86 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 22500 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 915 kN and C0 1040 kN, size the bearing on the 120×260 mm ISO 15 envelope and check the 116 kN Pu against the equivalent-load floor; the catalogue lists 2,800 r/min thermal reference speed and 5,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2324, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2324 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 86 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 86 mm-wide ring and concentrates load.",
      "The 915/1040 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2324-ECML?",
        "a": "SKF NU 2324 ECML is a single-row caged cylindrical roller bearing with 120 mm bore, 260 mm OD and 86 mm width per ISO 15. SKF lists C 915 kN, C0 1040 kN, Pu 116 kN, reference speed 2,800 r/min and limiting speed 5,000 r/min, mass about 22500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2324-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2324-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2324",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×260×86 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2324-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×86 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2324-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×86 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2324-ECML",
      "SKF NU 2324 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2326-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2326 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 93,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1060,
    "static_load_kN": 1250,
    "fatigue_load_limit_kN": 137,
    "max_rpm": 4500,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 4500,
    "weight_g": 28500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2326-ECML is the 130 mm bore entry in the NU2300 range: a 130×280×93 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1060 kN / C0 1250 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Load-per-bore for the 130 mm seat is about 8.15 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 1250 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2326, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2326 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 93 mm-wide ring and concentrates load.",
      "The 1060/1250 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2326-ECML?",
        "a": "SKF NU 2326 ECML is a single-row caged cylindrical roller bearing with 130 mm bore, 280 mm OD and 93 mm width per ISO 15. SKF lists C 1060 kN, C0 1250 kN, Pu 137 kN, reference speed 2,400 r/min and limiting speed 4,500 r/min, mass about 28500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2326-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2326-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2326",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×280×93 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2326-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×93 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2326-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×93 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2326-ECML",
      "SKF NU 2326 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2328-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2328 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1200,
    "static_load_kN": 1430,
    "fatigue_load_limit_kN": 150,
    "max_rpm": 4300,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 4300,
    "weight_g": 36000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2328 ECML is a single-row caged cylindrical roller bearing sized 140×300×102 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.19 (1430 against 1200 kN), and the Pu figure 150 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,400 r/min thermal reference speed and 4,300 r/min mechanical limiting speed. Fit practice for NU2328-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2328, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2328 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 300 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1200/1430 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2328-ECML?",
        "a": "SKF NU 2328 ECML is a single-row caged cylindrical roller bearing with 140 mm bore, 300 mm OD and 102 mm width per ISO 15. SKF lists C 1200 kN, C0 1430 kN, Pu 150 kN, reference speed 2,400 r/min and limiting speed 4,300 r/min, mass about 36000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2328-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2328-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2328",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×300×102 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2328-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×102 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP2328-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×102 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2328-ECML",
      "SKF NU 2328 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2330-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2330 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 320,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1370,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 170,
    "max_rpm": 4000,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 4000,
    "weight_g": 42500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2330 ECML is a single-row caged cylindrical roller bearing sized 150×320×108 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.19 (1630 against 1370 kN), and the Pu figure 170 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,200 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Fit practice for NU2330-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2330, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2330 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1370/1630 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2330-ECML?",
        "a": "SKF NU 2330 ECML is a single-row caged cylindrical roller bearing with 150 mm bore, 320 mm OD and 108 mm width per ISO 15. SKF lists C 1370 kN, C0 1630 kN, Pu 170 kN, reference speed 2,200 r/min and limiting speed 4,000 r/min, mass about 42500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2330-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2330-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2330",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 150×320×108 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2330-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×320×108 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2330-ECML",
      "SKF NU 2330 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2332-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2332 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 114,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1250,
    "static_load_kN": 1730,
    "fatigue_load_limit_kN": 173,
    "max_rpm": 3600,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 3600,
    "weight_g": 50000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2332 ECML resolves to a 160×340×114 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 1250 kN and C0 1730 kN, size the bearing on the 160×340 mm ISO 15 envelope and check the 173 kN Pu against the equivalent-load floor; the catalogue lists 1,800 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. Fit practice for NU2332-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2332, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2332 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 340 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1250/1730 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2332-ECML?",
        "a": "SKF NU 2332 ECML is a single-row caged cylindrical roller bearing with 160 mm bore, 340 mm OD and 114 mm width per ISO 15. SKF lists C 1250 kN, C0 1730 kN, Pu 173 kN, reference speed 1,800 r/min and limiting speed 3,600 r/min, mass about 50000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2332-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2332-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2332",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 160×340×114 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2332-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×340×114 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2332-ECML",
      "SKF NU 2332 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2334-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2334 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 360,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1450,
    "static_load_kN": 2040,
    "fatigue_load_limit_kN": 204,
    "max_rpm": 3400,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 3400,
    "weight_g": 60500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 170 mm shaft, SKF lists NU2334-ECML as single-row caged cylindrical roller: 360 mm OD, 120 mm wide, Pu 204 kN, the catalogue lists 1,700 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 170 mm seat is about 8.53 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 2040 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2334-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2334, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2334 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 120 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1450/2040 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2334-ECML?",
        "a": "SKF NU 2334 ECML is a single-row caged cylindrical roller bearing with 170 mm bore, 360 mm OD and 120 mm width per ISO 15. SKF lists C 1450 kN, C0 2040 kN, Pu 204 kN, reference speed 1,700 r/min and limiting speed 3,400 r/min, mass about 60500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2334-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2334-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2334",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 170×360×120 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2334-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 170×360×120 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2334-ECML",
      "SKF NU 2334 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2336-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2336 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 380,
    "B_mm": 126,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1610,
    "static_load_kN": 2240,
    "fatigue_load_limit_kN": 216,
    "max_rpm": 3200,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 3200,
    "weight_g": 69500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2336 ECML resolves to a 180×380×126 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.39 (2240 against 1610 kN), and the Pu figure 216 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. Fit practice for NU2336-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2336, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2336 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "The 1610/2240 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2336-ECML?",
        "a": "SKF NU 2336 ECML is a single-row caged cylindrical roller bearing with 180 mm bore, 380 mm OD and 126 mm width per ISO 15. SKF lists C 1610 kN, C0 2240 kN, Pu 216 kN, reference speed 1,600 r/min and limiting speed 3,200 r/min, mass about 69500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2336-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2336-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2336",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 180×380×126 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2336-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×380×126 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2336-ECML",
      "SKF NU 2336 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2338-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2338 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 400,
    "B_mm": 132,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1830,
    "static_load_kN": 2550,
    "fatigue_load_limit_kN": 236,
    "max_rpm": 3000,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 3000,
    "weight_g": 80500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 190 mm shaft, SKF lists NU2338-ECML as single-row caged cylindrical roller: 400 mm OD, 132 mm wide, Pu 236 kN, the catalogue lists 1,500 r/min thermal reference speed and 3,000 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1830 kN and C0 2550 kN, size the bearing on the 190×400 mm ISO 15 envelope and check the 236 kN Pu against the equivalent-load floor; the catalogue lists 1,500 r/min thermal reference speed and 3,000 r/min mechanical limiting speed. Fit practice for NU2338-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2338, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2338 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 1830/2550 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2338-ECML?",
        "a": "SKF NU 2338 ECML is a single-row caged cylindrical roller bearing with 190 mm bore, 400 mm OD and 132 mm width per ISO 15. SKF lists C 1830 kN, C0 2550 kN, Pu 236 kN, reference speed 1,500 r/min and limiting speed 3,000 r/min, mass about 80500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2338-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2338-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2338",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 190×400×132 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2338-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×400×132 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2338-ECML",
      "SKF NU 2338 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU234-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 234 ECML",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 695,
    "static_load_kN": 815,
    "fatigue_load_limit_kN": 85,
    "max_rpm": 3800,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 3800,
    "weight_g": 17500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU234-ECML is the 170 mm bore entry in the NU200 range: a 170×310×52 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 695 kN / C0 815 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.17 (815 against 695 kN), and the Pu figure 85 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,200 r/min thermal reference speed and 3,800 r/min mechanical limiting speed. Fit practice for NU234-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 234, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 234 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 310 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 695/815 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU234-ECML?",
        "a": "SKF NU 234 ECML is a single-row caged cylindrical roller bearing with 170 mm bore, 310 mm OD and 52 mm width per ISO 15. SKF lists C 695 kN, C0 815 kN, Pu 85 kN, reference speed 2,200 r/min and limiting speed 3,800 r/min, mass about 17500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU234-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU234-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU234",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 170×310×52 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ234-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 170×310×52 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU234-ECML",
      "SKF NU 234 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2340-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2340 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 420,
    "B_mm": 138,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1980,
    "static_load_kN": 2800,
    "fatigue_load_limit_kN": 255,
    "max_rpm": 2800,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 2800,
    "weight_g": 92500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2340-ECML is the 200 mm bore entry in the NU2300 range: a 200×420×138 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1980 kN / C0 2800 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Speed planning for NU2340-ECML: the catalogue lists 1,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. The mass entry 92500 g covers the complete catalogue execution. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 200 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2340, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2340 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 420 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 420 mm raceway.",
      "The 1980/2800 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2340-ECML?",
        "a": "SKF NU 2340 ECML is a single-row caged cylindrical roller bearing with 200 mm bore, 420 mm OD and 138 mm width per ISO 15. SKF lists C 1980 kN, C0 2800 kN, Pu 255 kN, reference speed 1,400 r/min and limiting speed 2,800 r/min, mass about 92500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2340-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2340-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2340",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 200×420×138 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2340-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×420×138 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2340-ECML",
      "SKF NU 2340 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2344-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2344 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 460,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2380,
    "static_load_kN": 3450,
    "fatigue_load_limit_kN": 310,
    "max_rpm": 2600,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 2600,
    "weight_g": 118000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2344-ECML is the 220 mm bore entry in the NU2300 range: a 220×460×145 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 2380 kN / C0 3450 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 120.0 mm and the catalogue mass 118000 g; at 2380 kN dynamic rating this is roughly 10.82 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 220 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2344, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2344 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 145 mm-wide ring and concentrates load.",
      "The 2380/3450 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2344-ECML?",
        "a": "SKF NU 2344 ECML is a single-row caged cylindrical roller bearing with 220 mm bore, 460 mm OD and 145 mm width per ISO 15. SKF lists C 2380 kN, C0 3450 kN, Pu 310 kN, reference speed 1,300 r/min and limiting speed 2,600 r/min, mass about 118000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2344-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2344-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2344",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 220×460×145 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU2344",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2344-ECML",
      "SKF NU 2344 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2348-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2348 ECML",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 500,
    "B_mm": 155,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2750,
    "static_load_kN": 4000,
    "fatigue_load_limit_kN": 345,
    "max_rpm": 2400,
    "reference_speed_rpm": 1200,
    "limiting_speed_rpm": 2400,
    "weight_g": 137000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2348-ECML is the 240 mm bore entry in the NU2300 range: a 240×500×155 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 2750 kN / C0 4000 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Load-per-bore for the 240 mm seat is about 11.46 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 4000 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2348-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2348, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2348 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 500 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 155 mm-wide ring and concentrates load.",
      "The 2750/4000 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2348-ECML?",
        "a": "SKF NU 2348 ECML is a single-row caged cylindrical roller bearing with 240 mm bore, 500 mm OD and 155 mm width per ISO 15. SKF lists C 2750 kN, C0 4000 kN, Pu 345 kN, reference speed 1,200 r/min and limiting speed 2,400 r/min, mass about 137000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2348-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2348-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2348",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 240×500×155 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU2348",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2348-ECML",
      "SKF NU 2348 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2352-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2352 ECMA",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 260,
    "D_mm": 540,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3190,
    "static_load_kN": 4550,
    "fatigue_load_limit_kN": 400,
    "max_rpm": 1800,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1800,
    "weight_g": 193000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2352 ECMA denotes a single-row caged cylindrical roller bearing on the ISO 15 260×540×165 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 193000 g. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 140.0 mm and the catalogue mass 193000 g; at 3190 kN dynamic rating this is roughly 12.27 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 260 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2352, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2352 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 540 mm raceway.",
      "The 3190/4550 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2352-ECMA?",
        "a": "SKF NU 2352 ECMA is a single-row caged cylindrical roller bearing with 260 mm bore, 540 mm OD and 165 mm width per ISO 15. SKF lists C 3190 kN, C0 4550 kN, Pu 400 kN, reference speed 1,100 r/min and limiting speed 1,800 r/min, mass about 193000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2352-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2352-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2352",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 260×540×165 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2352-ECMA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 260×540×165 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2352-ECMA",
      "SKF NU 2352 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2356-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2356 MA",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 280,
    "D_mm": 580,
    "B_mm": 175,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2700,
    "static_load_kN": 4300,
    "fatigue_load_limit_kN": 365,
    "max_rpm": 1700,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1700,
    "weight_g": 230000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 2356 MA denotes a single-row caged cylindrical roller bearing on the ISO 15 280×580×175 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 230000 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. Load-per-bore for the 280 mm seat is about 9.64 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 4300 kN for static checks such as crane hook blocks standing under load. Fit practice for NU2356-MA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2356, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2356 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 580 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 580 mm raceway.",
      "The 2700/4300 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2356-MA?",
        "a": "SKF NU 2356 MA is a single-row caged cylindrical roller bearing with 280 mm bore, 580 mm OD and 175 mm width per ISO 15. SKF lists C 2700 kN, C0 4300 kN, Pu 365 kN, reference speed 1,000 r/min and limiting speed 1,700 r/min, mass about 230000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2356-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2356-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2356",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NU2356",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2356-MA",
      "SKF NU 2356 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU236-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 236 ECML",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 720,
    "static_load_kN": 850,
    "fatigue_load_limit_kN": 88,
    "max_rpm": 3600,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 3600,
    "weight_g": 18500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 236 ECML is a single-row caged cylindrical roller bearing sized 180×320×52 mm — a dimension series 2 (light-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 720 kN and C0 850 kN, size the bearing on the 180×320 mm ISO 15 envelope and check the 88 kN Pu against the equivalent-load floor; the catalogue lists 2,200 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. Fit practice for NU236-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 236, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 236 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 52 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 720/850 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU236-ECML?",
        "a": "SKF NU 236 ECML is a single-row caged cylindrical roller bearing with 180 mm bore, 320 mm OD and 52 mm width per ISO 15. SKF lists C 720 kN, C0 850 kN, Pu 88 kN, reference speed 2,200 r/min and limiting speed 3,600 r/min, mass about 18500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU236-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU236-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU236",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 180×320×52 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ236-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×320×52 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU236-ECML",
      "SKF NU 236 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2360-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2360 ECMA",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 300,
    "D_mm": 620,
    "B_mm": 185,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 4020,
    "static_load_kN": 5850,
    "fatigue_load_limit_kN": 480,
    "max_rpm": 1600,
    "reference_speed_rpm": 950,
    "limiting_speed_rpm": 1600,
    "weight_g": 270000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU2360-ECMA is the 300 mm bore entry in the NU2300 range: a 300×620×185 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 4020 kN / C0 5850 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 160.0 mm and the catalogue mass 270000 g; at 4020 kN dynamic rating this is roughly 13.40 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 300 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2360, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2360 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 185 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 185 mm-wide ring and concentrates load.",
      "The 4020/5850 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2360-ECMA?",
        "a": "SKF NU 2360 ECMA is a single-row caged cylindrical roller bearing with 300 mm bore, 620 mm OD and 185 mm width per ISO 15. SKF lists C 4020 kN, C0 5850 kN, Pu 480 kN, reference speed 950 r/min and limiting speed 1,600 r/min, mass about 270000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2360-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2360-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2360",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2360-ECMA",
      "SKF NU 2360 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2364-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2364 ECMA",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 320,
    "D_mm": 670,
    "B_mm": 200,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 4730,
    "static_load_kN": 7500,
    "fatigue_load_limit_kN": 600,
    "max_rpm": 1500,
    "reference_speed_rpm": 850,
    "limiting_speed_rpm": 1500,
    "weight_g": 370000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2364 ECMA resolves to a 320×670×200 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.59 (7500 against 4730 kN), and the Pu figure 600 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 850 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 320 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2364, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2364 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 670 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 200 mm-wide ring and concentrates load.",
      "The 4730/7500 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2364-ECMA?",
        "a": "SKF NU 2364 ECMA is a single-row caged cylindrical roller bearing with 320 mm bore, 670 mm OD and 200 mm width per ISO 15. SKF lists C 4730 kN, C0 7500 kN, Pu 600 kN, reference speed 850 r/min and limiting speed 1,500 r/min, mass about 370000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2364-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2364-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2364",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2364-ECMA",
      "SKF NU 2364 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2368-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2368 ECMA",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 340,
    "D_mm": 710,
    "B_mm": 212,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5610,
    "static_load_kN": 8650,
    "fatigue_load_limit_kN": 680,
    "max_rpm": 1400,
    "reference_speed_rpm": 800,
    "limiting_speed_rpm": 1400,
    "weight_g": 439000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2368 ECMA resolves to a 340×710×212 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Speed planning for NU2368-ECMA: the catalogue lists 800 r/min thermal reference speed and 1,400 r/min mechanical limiting speed. The mass entry 439000 g covers the complete catalogue execution. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 340 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2368, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2368 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5610/8650 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2368-ECMA?",
        "a": "SKF NU 2368 ECMA is a single-row caged cylindrical roller bearing with 340 mm bore, 710 mm OD and 212 mm width per ISO 15. SKF lists C 5610 kN, C0 8650 kN, Pu 680 kN, reference speed 800 r/min and limiting speed 1,400 r/min, mass about 439000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2368-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2368-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2368",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2368-ECMA",
      "SKF NU 2368 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2372-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2372 ECMA",
    "series": "NU2300-series",
    "type": "cylindrical_roller",
    "d_mm": 360,
    "D_mm": 750,
    "B_mm": 224,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5010,
    "static_load_kN": 8150,
    "fatigue_load_limit_kN": 630,
    "max_rpm": 1300,
    "reference_speed_rpm": 850,
    "limiting_speed_rpm": 1300,
    "weight_g": 510000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 360 mm shaft, SKF lists NU2372-ECMA as single-row caged cylindrical roller: 750 mm OD, 224 mm wide, Pu 630 kN, the catalogue lists 850 r/min thermal reference speed and 1,300 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.63 (8150 against 5010 kN), and the Pu figure 630 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 850 r/min thermal reference speed and 1,300 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 360 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2372, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2372 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5010/8150 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2372-ECMA?",
        "a": "SKF NU 2372 ECMA is a single-row caged cylindrical roller bearing with 360 mm bore, 750 mm OD and 224 mm width per ISO 15. SKF lists C 5010 kN, C0 8150 kN, Pu 630 kN, reference speed 850 r/min and limiting speed 1,300 r/min, mass about 510000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2372-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2372-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2372",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2372-ECMA",
      "SKF NU 2372 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU238-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 238 ECML",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 800,
    "static_load_kN": 965,
    "fatigue_load_limit_kN": 98,
    "max_rpm": 3400,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 3400,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU238-ECML is the 190 mm bore entry in the NU200 range: a 190×340×55 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 800 kN / C0 965 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Speed planning for NU238-ECML: the catalogue lists 2,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. The mass entry 22500 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 238, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 238 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 55 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 800/965 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU238-ECML?",
        "a": "SKF NU 238 ECML is a single-row caged cylindrical roller bearing with 190 mm bore, 340 mm OD and 55 mm width per ISO 15. SKF lists C 800 kN, C0 965 kN, Pu 98 kN, reference speed 2,000 r/min and limiting speed 3,400 r/min, mass about 22500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU238-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU238-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU238",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 190×340×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ238-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×340×55 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP238-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×340×55 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU238-ECML",
      "SKF NU 238 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU240-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 240 ECML",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 880,
    "static_load_kN": 1060,
    "fatigue_load_limit_kN": 106,
    "max_rpm": 3200,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 3200,
    "weight_g": 26500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 240 ECML resolves to a 200×360×58 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 200 mm seat is about 4.40 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 1060 kN for static checks such as crane hook blocks standing under load. Fit practice for NU240-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 240, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 240 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 58 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 880/1060 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU240-ECML?",
        "a": "SKF NU 240 ECML is a single-row caged cylindrical roller bearing with 200 mm bore, 360 mm OD and 58 mm width per ISO 15. SKF lists C 880 kN, C0 1060 kN, Pu 106 kN, reference speed 1,900 r/min and limiting speed 3,200 r/min, mass about 26500 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU240-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU240-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU240",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 200×360×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ240-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×360×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU240-ECML",
      "SKF NU 240 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU244-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 244 ECML",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 400,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1060,
    "static_load_kN": 1290,
    "fatigue_load_limit_kN": 125,
    "max_rpm": 3000,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 3000,
    "weight_g": 37000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 244 ECML resolves to a 220×400×65 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1060 kN and C0 1290 kN, size the bearing on the 220×400 mm ISO 15 envelope and check the 125 kN Pu against the equivalent-load floor; the catalogue lists 1,700 r/min thermal reference speed and 3,000 r/min mechanical limiting speed. Fit practice for NU244-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 244, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 244 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 1060/1290 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU244-ECML?",
        "a": "SKF NU 244 ECML is a single-row caged cylindrical roller bearing with 220 mm bore, 400 mm OD and 65 mm width per ISO 15. SKF lists C 1060 kN, C0 1290 kN, Pu 125 kN, reference speed 1,700 r/min and limiting speed 3,000 r/min, mass about 37000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU244-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU244-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU244",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 220×400×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ244-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×65 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP244-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×65 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU244-ECML",
      "SKF NU 244 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU248-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 248 MA",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 952,
    "static_load_kN": 1370,
    "fatigue_load_limit_kN": 129,
    "max_rpm": 2200,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 2200,
    "weight_g": 51500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 248 MA denotes a single-row caged cylindrical roller bearing on the ISO 15 240×440×72 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 51500 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. Selection arithmetic: C0/C ≈ 1.44 (1370 against 952 kN), and the Pu figure 129 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 240 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 248, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 248 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 72 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 952/1370 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU248-MA?",
        "a": "SKF NU 248 MA is a single-row caged cylindrical roller bearing with 240 mm bore, 440 mm OD and 72 mm width per ISO 15. SKF lists C 952 kN, C0 1370 kN, Pu 129 kN, reference speed 1,600 r/min and limiting speed 2,200 r/min, mass about 51500 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU248-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU248-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU248",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ248-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 240×440×72 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP248-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 240×440×72 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU248-MA",
      "SKF NU 248 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU252-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 252 MA",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 260,
    "D_mm": 480,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1170,
    "static_load_kN": 1700,
    "fatigue_load_limit_kN": 150,
    "max_rpm": 2000,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 2000,
    "weight_g": 68500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 252 MA denotes a single-row caged cylindrical roller bearing on the ISO 15 260×480×80 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 68500 g. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 1170 kN and C0 1700 kN, size the bearing on the 260×480 mm ISO 15 envelope and check the 150 kN Pu against the equivalent-load floor; the catalogue lists 1,400 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 260 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 252, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 252 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 1170/1700 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU252-MA?",
        "a": "SKF NU 252 MA is a single-row caged cylindrical roller bearing with 260 mm bore, 480 mm OD and 80 mm width per ISO 15. SKF lists C 1170 kN, C0 1700 kN, Pu 150 kN, reference speed 1,400 r/min and limiting speed 2,000 r/min, mass about 68500 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU252-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU252-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU252",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ252-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 260×480×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP252-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 260×480×80 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU252-MA",
      "SKF NU 252 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU256-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 256 MA",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 280,
    "D_mm": 500,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1190,
    "static_load_kN": 1800,
    "fatigue_load_limit_kN": 156,
    "max_rpm": 1900,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 1900,
    "weight_g": 71500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 256 MA is a single-row caged cylindrical roller bearing sized 280×500×80 mm — a dimension series 2 (light-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 110.0 mm and the catalogue mass 71500 g; at 1190 kN dynamic rating this is roughly 4.25 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 256, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 256 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 1190/1800 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU256-MA?",
        "a": "SKF NU 256 MA is a single-row caged cylindrical roller bearing with 280 mm bore, 500 mm OD and 80 mm width per ISO 15. SKF lists C 1190 kN, C0 1800 kN, Pu 156 kN, reference speed 1,400 r/min and limiting speed 1,900 r/min, mass about 71500 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU256-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU256-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU256",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ256-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 280×500×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU256-MA",
      "SKF NU 256 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU260-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 260 M",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 300,
    "D_mm": 540,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1420,
    "static_load_kN": 2120,
    "fatigue_load_limit_kN": 183,
    "max_rpm": 1400,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 1400,
    "weight_g": 89500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU260-M is the 300 mm bore entry in the NU200 range: a 300×540×85 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1420 kN / C0 2120 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Speed planning for NU260-M: the catalogue lists 1,300 r/min thermal reference speed and 1,400 r/min mechanical limiting speed. The mass entry 89500 g covers the complete catalogue execution. Fit practice for NU260-M: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 260, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 260 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1420/2120 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU260-M?",
        "a": "SKF NU 260 M is a single-row caged cylindrical roller bearing with 300 mm bore, 540 mm OD and 85 mm width per ISO 15. SKF lists C 1420 kN, C0 2120 kN, Pu 183 kN, reference speed 1,300 r/min and limiting speed 1,400 r/min, mass about 89500 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU260-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU260-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU260",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NU260",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU260-M",
      "SKF NU 260 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU264-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 264 ECM",
    "series": "NU200-series",
    "type": "cylindrical_roller",
    "d_mm": 320,
    "D_mm": 580,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1830,
    "static_load_kN": 2750,
    "fatigue_load_limit_kN": 232,
    "max_rpm": 1200,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1200,
    "weight_g": 115000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU264-ECM is the 320 mm bore entry in the NU200 range: a 320×580×92 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1830 kN / C0 2750 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 1830 kN and C0 2750 kN, size the bearing on the 320×580 mm ISO 15 envelope and check the 232 kN Pu against the equivalent-load floor; the catalogue lists 1,000 r/min thermal reference speed and 1,200 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 264, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 264 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 580 mm raceway.",
      "The 1830/2750 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU264-ECM?",
        "a": "SKF NU 264 ECM is a single-row caged cylindrical roller bearing with 320 mm bore, 580 mm OD and 92 mm width per ISO 15. SKF lists C 1830 kN, C0 2750 kN, Pu 232 kN, reference speed 1,000 r/min and limiting speed 1,200 r/min, mass about 115000 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU264-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU264-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU264",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 320×580×92 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU264",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU264-ECM",
      "SKF NU 264 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU28-850-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 28/850 MA",
    "series": "NU2800-series",
    "type": "cylindrical_roller",
    "d_mm": 850,
    "D_mm": 1030,
    "B_mm": 106,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2120,
    "static_load_kN": 6000,
    "fatigue_load_limit_kN": 240,
    "max_rpm": 670,
    "reference_speed_rpm": 500,
    "limiting_speed_rpm": 670,
    "weight_g": 193000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 28/850 MA is a single-row caged cylindrical roller bearing sized 850×1030×106 mm — a dimension series 28 (slim section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. Load-per-bore for the 850 mm seat is about 2.49 kN/mm, typical of dimension series 28 (slim section, wide); use C0 6000 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 28 (slim section, wide) envelope is shared with the N/NU/NJ/NUP executions of 28/850, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 28/850 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 106 mm-wide ring and concentrates load.",
      "The 2120/6000 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU28-850-MA?",
        "a": "SKF NU 28/850 MA is a single-row caged cylindrical roller bearing with 850 mm bore, 1030 mm OD and 106 mm width per ISO 15. SKF lists C 2120 kN, C0 6000 kN, Pu 240 kN, reference speed 500 r/min and limiting speed 670 r/min, mass about 193000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU28-850-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU28-850-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU28",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU28-850-MA",
      "SKF NU 28/850 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU29-500-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 29/500 ECMA",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 500,
    "D_mm": 670,
    "B_mm": 100,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2050,
    "static_load_kN": 4250,
    "fatigue_load_limit_kN": 355,
    "max_rpm": 1200,
    "reference_speed_rpm": 900,
    "limiting_speed_rpm": 1200,
    "weight_g": 107000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 29/500 ECMA denotes a single-row caged cylindrical roller bearing on the ISO 15 500×670×100 mm envelope, dimension series 29 (compact OD, normal width), with catalogue mass 107000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 2050 kN and C0 4250 kN, size the bearing on the 500×670 mm ISO 15 envelope and check the 355 kN Pu against the equivalent-load floor; the catalogue lists 900 r/min thermal reference speed and 1,200 r/min mechanical limiting speed. Fit practice for NU29-500-ECMA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/500, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 29/500 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 100 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 2050/4250 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU29-500-ECMA?",
        "a": "SKF NU 29/500 ECMA is a single-row caged cylindrical roller bearing with 500 mm bore, 670 mm OD and 100 mm width per ISO 15. SKF lists C 2050 kN, C0 4250 kN, Pu 355 kN, reference speed 900 r/min and limiting speed 1,200 r/min, mass about 107000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU29-500-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU29-500-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU29-500-ECMA",
      "SKF NU 29/500 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU29-560-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 29/560 ECMA",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 560,
    "D_mm": 750,
    "B_mm": 112,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2460,
    "static_load_kN": 5700,
    "fatigue_load_limit_kN": 450,
    "max_rpm": 1000,
    "reference_speed_rpm": 800,
    "limiting_speed_rpm": 1000,
    "weight_g": 145000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU29-560-ECMA is the 560 mm bore entry in the NU2900 range: a 560×750×112 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 2460 kN / C0 5700 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 2460 kN and C0 5700 kN, size the bearing on the 560×750 mm ISO 15 envelope and check the 450 kN Pu against the equivalent-load floor; the catalogue lists 800 r/min thermal reference speed and 1,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 560 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/560, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 29/560 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 112 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 112 mm-wide ring and concentrates load.",
      "The 2460/5700 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU29-560-ECMA?",
        "a": "SKF NU 29/560 ECMA is a single-row caged cylindrical roller bearing with 560 mm bore, 750 mm OD and 112 mm width per ISO 15. SKF lists C 2460 kN, C0 5700 kN, Pu 450 kN, reference speed 800 r/min and limiting speed 1,000 r/min, mass about 145000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU29-560-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU29-560-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU29-560-ECMA",
      "SKF NU 29/560 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU29-630-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 29/630 ECMA/HB1",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 630,
    "D_mm": 850,
    "B_mm": 128,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3300,
    "static_load_kN": 7200,
    "fatigue_load_limit_kN": 510,
    "max_rpm": 900,
    "reference_speed_rpm": 700,
    "limiting_speed_rpm": 900,
    "weight_g": 224000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 630 mm shaft, SKF lists NU29-630-ECMA-HB1 as single-row caged cylindrical roller: 850 mm OD, 128 mm wide, Pu 510 kN, the catalogue lists 700 r/min thermal reference speed and 900 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 3300 kN and C0 7200 kN, size the bearing on the 630×850 mm ISO 15 envelope and check the 510 kN Pu against the equivalent-load floor; the catalogue lists 700 r/min thermal reference speed and 900 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 630 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/630, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 29/630 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 128 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 128 mm-wide ring and concentrates load.",
      "The 3300/7200 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU29-630-ECMA-HB1?",
        "a": "SKF NU 29/630 ECMA/HB1 is a single-row caged cylindrical roller bearing with 630 mm bore, 850 mm OD and 128 mm width per ISO 15. SKF lists C 3300 kN, C0 7200 kN, Pu 510 kN, reference speed 700 r/min and limiting speed 900 r/min, mass about 224000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU29-630-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU29-630-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ29-630-ECMA-HB1",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 630×850×128 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU29-630-ECMA-HB1",
      "SKF NU 29/630 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU29-710-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 29/710 ECMA",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 710,
    "D_mm": 950,
    "B_mm": 140,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3740,
    "static_load_kN": 8300,
    "fatigue_load_limit_kN": 570,
    "max_rpm": 800,
    "reference_speed_rpm": 600,
    "limiting_speed_rpm": 800,
    "weight_g": 297000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 29/710 ECMA is a single-row caged cylindrical roller bearing sized 710×950×140 mm — a dimension series 29 (compact OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 710 mm seat is about 5.27 kN/mm, typical of dimension series 29 (compact OD, normal width); use C0 8300 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 710 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/710, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 29/710 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 950 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 140 mm-wide ring and concentrates load.",
      "The 3740/8300 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU29-710-ECMA?",
        "a": "SKF NU 29/710 ECMA is a single-row caged cylindrical roller bearing with 710 mm bore, 950 mm OD and 140 mm width per ISO 15. SKF lists C 3740 kN, C0 8300 kN, Pu 570 kN, reference speed 600 r/min and limiting speed 800 r/min, mass about 297000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU29-710-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU29-710-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU29-710-ECMA",
      "SKF NU 29/710 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU29-900-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 29/900 ECMA/HB1",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 900,
    "D_mm": 1180,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5280,
    "static_load_kN": 12500,
    "fatigue_load_limit_kN": 800,
    "max_rpm": 560,
    "reference_speed_rpm": 430,
    "limiting_speed_rpm": 560,
    "weight_g": 514000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 29/900 ECMA/HB1 is a single-row caged cylindrical roller bearing sized 900×1180×165 mm — a dimension series 29 (compact OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 900 mm seat is about 5.87 kN/mm, typical of dimension series 29 (compact OD, normal width); use C0 12500 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/900, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 29/900 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5280/12500 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU29-900-ECMA-HB1?",
        "a": "SKF NU 29/900 ECMA/HB1 is a single-row caged cylindrical roller bearing with 900 mm bore, 1180 mm OD and 165 mm width per ISO 15. SKF lists C 5280 kN, C0 12500 kN, Pu 800 kN, reference speed 430 r/min and limiting speed 560 r/min, mass about 514000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU29-900-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU29-900-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU29-900-ECMA-HB1",
      "SKF NU 29/900 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2984-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2984 ECMA",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 420,
    "D_mm": 560,
    "B_mm": 82,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1400,
    "static_load_kN": 2850,
    "fatigue_load_limit_kN": 255,
    "max_rpm": 1500,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1500,
    "weight_g": 60000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 2984 ECMA resolves to a 420×560×82 mm single-row caged cylindrical roller bearing (dimension series 29 (compact OD, normal width)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Speed planning for NU2984-ECMA: the catalogue lists 1,100 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. The mass entry 60000 g covers the complete catalogue execution. Fit practice for NU2984-ECMA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 2984, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2984 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 560 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 82 mm-wide ring and concentrates load.",
      "The 1400/2850 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2984-ECMA?",
        "a": "SKF NU 2984 ECMA is a single-row caged cylindrical roller bearing with 420 mm bore, 560 mm OD and 82 mm width per ISO 15. SKF lists C 1400 kN, C0 2850 kN, Pu 255 kN, reference speed 1,100 r/min and limiting speed 1,500 r/min, mass about 60000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2984-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2984-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU2984",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2984-ECMA",
      "SKF NU 2984 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU2988-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 2988 ECML",
    "series": "NU2900-series",
    "type": "cylindrical_roller",
    "d_mm": 440,
    "D_mm": 600,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1870,
    "static_load_kN": 3900,
    "fatigue_load_limit_kN": 340,
    "max_rpm": 1600,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1600,
    "weight_g": 81000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 2988 ECML is a single-row caged cylindrical roller bearing sized 440×600×95 mm — a dimension series 29 (compact OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1870 kN and C0 3900 kN, size the bearing on the 440×600 mm ISO 15 envelope and check the 340 kN Pu against the equivalent-load floor; the catalogue lists 1,100 r/min thermal reference speed and 1,600 r/min mechanical limiting speed. Fit practice for NU2988-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 2988, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2988 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 95 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 600 mm raceway.",
      "The 1870/3900 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU2988-ECML?",
        "a": "SKF NU 2988 ECML is a single-row caged cylindrical roller bearing with 440 mm bore, 600 mm OD and 95 mm width per ISO 15. SKF lists C 1870 kN, C0 3900 kN, Pu 340 kN, reference speed 1,100 r/min and limiting speed 1,600 r/min, mass about 81000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU2988-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU2988-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2988-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 440×600×95 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU2988-ECML",
      "SKF NU 2988 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU30-500-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 30/500 ECMA",
    "series": "NU3000-series",
    "type": "cylindrical_roller",
    "d_mm": 500,
    "D_mm": 720,
    "B_mm": 167,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3800,
    "static_load_kN": 7350,
    "fatigue_load_limit_kN": 560,
    "max_rpm": 1100,
    "reference_speed_rpm": 750,
    "limiting_speed_rpm": 1100,
    "weight_g": 233000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU30-500-ECMA is the 500 mm bore entry in the NU3000 range: a 500×720×167 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 3800 kN / C0 7350 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Load-per-bore for the 500 mm seat is about 7.60 kN/mm, typical of dimension series 30 (compact OD, normal width); use C0 7350 kN for static checks such as crane hook blocks standing under load. Fit practice for NU30-500-ECMA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 30 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 30/500, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 30/500 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 720 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 167 mm-wide ring and concentrates load.",
      "The 3800/7350 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU30-500-ECMA?",
        "a": "SKF NU 30/500 ECMA is a single-row caged cylindrical roller bearing with 500 mm bore, 720 mm OD and 167 mm width per ISO 15. SKF lists C 3800 kN, C0 7350 kN, Pu 560 kN, reference speed 750 r/min and limiting speed 1,100 r/min, mass about 233000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU30-500-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU30-500-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU30-500-ECMA",
      "SKF NU 30/500 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU303-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 303 ECP",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 28.5,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 2.55,
    "max_rpm": 20000,
    "reference_speed_rpm": 17000,
    "limiting_speed_rpm": 20000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU303-ECP is the 17 mm bore entry in the NU300 range: a 17×47×14 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 28.5 kN / C0 20.4 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 28.5 kN and C0 20.4 kN, size the bearing on the 17×47 mm ISO 15 envelope and check the 2.55 kN Pu against the equivalent-load floor; the catalogue lists 17,000 r/min thermal reference speed and 20,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts",
      "small pump rotor shafts",
      "small industrial electric-motor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 303, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 303 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 14 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 14 mm-wide ring and concentrates load.",
      "The 28.5/20.4 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU303-ECP?",
        "a": "SKF NU 303 ECP is a single-row caged cylindrical roller bearing with 17 mm bore, 47 mm OD and 14 mm width per ISO 15. SKF lists C 28.5 kN, C0 20.4 kN, Pu 2.55 kN, reference speed 17,000 r/min and limiting speed 20,000 r/min, mass about 120 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU303-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU303-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N303-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×47×14 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ303-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×47×14 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU303-ECP",
      "SKF NU 303 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3068-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3068 MA",
    "series": "NU3000-series",
    "type": "cylindrical_roller",
    "d_mm": 340,
    "D_mm": 520,
    "B_mm": 133,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2200,
    "static_load_kN": 4150,
    "fatigue_load_limit_kN": 365,
    "max_rpm": 1700,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1700,
    "weight_g": 109000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 3068 MA denotes a single-row caged cylindrical roller bearing on the ISO 15 340×520×133 mm envelope, dimension series 30 (compact OD, normal width), with catalogue mass 109000 g. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 340 mm seat is about 6.47 kN/mm, typical of dimension series 30 (compact OD, normal width); use C0 4150 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 30 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 3068, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3068 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 520 mm raceway.",
      "The 2200/4150 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3068-MA?",
        "a": "SKF NU 3068 MA is a single-row caged cylindrical roller bearing with 340 mm bore, 520 mm OD and 133 mm width per ISO 15. SKF lists C 2200 kN, C0 4150 kN, Pu 365 kN, reference speed 1,100 r/min and limiting speed 1,700 r/min, mass about 109000 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3068-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3068-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3068",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3068-MA",
      "SKF NU 3068 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3076-ECMP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3076 ECMP",
    "series": "NU3000-series",
    "type": "cylindrical_roller",
    "d_mm": 380,
    "D_mm": 560,
    "B_mm": 135,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2380,
    "static_load_kN": 4750,
    "fatigue_load_limit_kN": 400,
    "max_rpm": 1800,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1800,
    "weight_g": 109000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 3076 ECMP is a single-row caged cylindrical roller bearing sized 380×560×135 mm — a dimension series 30 (compact OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMP: the E-design ECMP execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. The radial section height is 90.0 mm and the catalogue mass 109000 g; at 2380 kN dynamic rating this is roughly 6.26 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 380 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 30 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 3076, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3076 ECMP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 135 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 2380/4750 kN ratings are SKF catalogue 17000 (2018) values for the ECMP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3076-ECMP?",
        "a": "SKF NU 3076 ECMP is a single-row caged cylindrical roller bearing with 380 mm bore, 560 mm OD and 135 mm width per ISO 15. SKF lists C 2380 kN, C0 4750 kN, Pu 400 kN, reference speed 1,000 r/min and limiting speed 1,800 r/min, mass about 109000 g."
      },
      {
        "q": "What does the NU designation and ECMP suffix mean?",
        "a": "The ECMP suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3076-ECMP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3076-ECMP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3076",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3076-ECMP",
      "SKF NU 3076 ECMP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU31-500-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 31/500 ECMA/HB1",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 500,
    "D_mm": 830,
    "B_mm": 264,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 6440,
    "static_load_kN": 12000,
    "fatigue_load_limit_kN": 880,
    "max_rpm": 1000,
    "reference_speed_rpm": 600,
    "limiting_speed_rpm": 1000,
    "weight_g": 595000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 31/500 ECMA/HB1 is a single-row caged cylindrical roller bearing sized 500×830×264 mm — a dimension series 31 (compact OD, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.86 (12000 against 6440 kN), and the Pu figure 880 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 600 r/min thermal reference speed and 1,000 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 31/500, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 31/500 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 264 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 830 mm raceway.",
      "The 6440/12000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU31-500-ECMA-HB1?",
        "a": "SKF NU 31/500 ECMA/HB1 is a single-row caged cylindrical roller bearing with 500 mm bore, 830 mm OD and 264 mm width per ISO 15. SKF lists C 6440 kN, C0 12000 kN, Pu 880 kN, reference speed 600 r/min and limiting speed 1,000 r/min, mass about 595000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU31-500-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU31-500-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU31",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU31-500-ECMA-HB1",
      "SKF NU 31/500 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU31-530-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 31/530 ECMA/HB1",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 530,
    "D_mm": 870,
    "B_mm": 272,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 7480,
    "static_load_kN": 14600,
    "fatigue_load_limit_kN": 1040,
    "max_rpm": 950,
    "reference_speed_rpm": 560,
    "limiting_speed_rpm": 950,
    "weight_g": 660000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 31/530 ECMA/HB1 denotes a single-row caged cylindrical roller bearing on the ISO 15 530×870×272 mm envelope, dimension series 31 (compact OD, wide), with catalogue mass 660000 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA/HB1: the basic execution supplied with a standard pressed-steel cage. Selection arithmetic: C0/C ≈ 1.95 (14600 against 7480 kN), and the Pu figure 1040 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 560 r/min thermal reference speed and 950 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 31/530, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 31/530 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 870 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 272 mm-wide ring and concentrates load.",
      "The 7480/14600 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU31-530-ECMA-HB1?",
        "a": "SKF NU 31/530 ECMA/HB1 is a single-row caged cylindrical roller bearing with 530 mm bore, 870 mm OD and 272 mm width per ISO 15. SKF lists C 7480 kN, C0 14600 kN, Pu 1040 kN, reference speed 560 r/min and limiting speed 950 r/min, mass about 660000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU31-530-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU31-530-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU31",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU31-530-ECMA-HB1",
      "SKF NU 31/530 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3156-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3156 ECMA",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 280,
    "D_mm": 460,
    "B_mm": 146,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2290,
    "static_load_kN": 3900,
    "fatigue_load_limit_kN": 335,
    "max_rpm": 2000,
    "reference_speed_rpm": 1200,
    "limiting_speed_rpm": 2000,
    "weight_g": 101000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 3156 ECMA denotes a single-row caged cylindrical roller bearing on the ISO 15 280×460×146 mm envelope, dimension series 31 (compact OD, wide), with catalogue mass 101000 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. With C 2290 kN and C0 3900 kN, size the bearing on the 280×460 mm ISO 15 envelope and check the 335 kN Pu against the equivalent-load floor; the catalogue lists 1,200 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 280 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3156, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3156 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 460 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 460 mm raceway.",
      "The 2290/3900 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3156-ECMA?",
        "a": "SKF NU 3156 ECMA is a single-row caged cylindrical roller bearing with 280 mm bore, 460 mm OD and 146 mm width per ISO 15. SKF lists C 2290 kN, C0 3900 kN, Pu 335 kN, reference speed 1,200 r/min and limiting speed 2,000 r/min, mass about 101000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3156-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3156-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3156",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3156-ECMA",
      "SKF NU 3156 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3168-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3168 ECMA",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 340,
    "D_mm": 580,
    "B_mm": 190,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3470,
    "static_load_kN": 5850,
    "fatigue_load_limit_kN": 490,
    "max_rpm": 1600,
    "reference_speed_rpm": 950,
    "limiting_speed_rpm": 1600,
    "weight_g": 217000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 3168 ECMA resolves to a 340×580×190 mm single-row caged cylindrical roller bearing (dimension series 31 (compact OD, wide)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.69 (5850 against 3470 kN), and the Pu figure 490 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 950 r/min thermal reference speed and 1,600 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3168, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3168 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 190 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 3470/5850 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3168-ECMA?",
        "a": "SKF NU 3168 ECMA is a single-row caged cylindrical roller bearing with 340 mm bore, 580 mm OD and 190 mm width per ISO 15. SKF lists C 3470 kN, C0 5850 kN, Pu 490 kN, reference speed 950 r/min and limiting speed 1,600 r/min, mass about 217000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3168-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3168-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3168",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3168-ECMA",
      "SKF NU 3168 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3172-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3172 ECMA",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 360,
    "D_mm": 600,
    "B_mm": 192,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3410,
    "static_load_kN": 6100,
    "fatigue_load_limit_kN": 490,
    "max_rpm": 1500,
    "reference_speed_rpm": 900,
    "limiting_speed_rpm": 1500,
    "weight_g": 226000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 360 mm shaft, SKF lists NU3172-ECMA as single-row caged cylindrical roller: 600 mm OD, 192 mm wide, Pu 490 kN, the catalogue lists 900 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Speed planning for NU3172-ECMA: the catalogue lists 900 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. The mass entry 226000 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3172, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3172 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 3410/6100 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3172-ECMA?",
        "a": "SKF NU 3172 ECMA is a single-row caged cylindrical roller bearing with 360 mm bore, 600 mm OD and 192 mm width per ISO 15. SKF lists C 3410 kN, C0 6100 kN, Pu 490 kN, reference speed 900 r/min and limiting speed 1,500 r/min, mass about 226000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3172-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3172-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3172",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3172-ECMA",
      "SKF NU 3172 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3184-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3184 ECMA",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 420,
    "D_mm": 700,
    "B_mm": 224,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 4950,
    "static_load_kN": 9000,
    "fatigue_load_limit_kN": 695,
    "max_rpm": 1300,
    "reference_speed_rpm": 750,
    "limiting_speed_rpm": 1300,
    "weight_g": 365000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 420 mm shaft, SKF lists NU3184-ECMA as single-row caged cylindrical roller: 700 mm OD, 224 mm wide, Pu 695 kN, the catalogue lists 750 r/min thermal reference speed and 1,300 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 140.0 mm and the catalogue mass 365000 g; at 4950 kN dynamic rating this is roughly 11.79 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 420 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3184, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3184 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 700 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 224 mm-wide ring and concentrates load.",
      "The 4950/9000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3184-ECMA?",
        "a": "SKF NU 3184 ECMA is a single-row caged cylindrical roller bearing with 420 mm bore, 700 mm OD and 224 mm width per ISO 15. SKF lists C 4950 kN, C0 9000 kN, Pu 695 kN, reference speed 750 r/min and limiting speed 1,300 r/min, mass about 365000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3184-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3184-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3184",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3184-ECMA",
      "SKF NU 3184 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3188-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3188 ECMA/HB1",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 440,
    "D_mm": 720,
    "B_mm": 226,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5120,
    "static_load_kN": 10000,
    "fatigue_load_limit_kN": 765,
    "max_rpm": 1200,
    "reference_speed_rpm": 700,
    "limiting_speed_rpm": 1200,
    "weight_g": 388000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 3188 ECMA/HB1 denotes a single-row caged cylindrical roller bearing on the ISO 15 440×720×226 mm envelope, dimension series 31 (compact OD, wide), with catalogue mass 388000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Selection arithmetic: C0/C ≈ 1.95 (10000 against 5120 kN), and the Pu figure 765 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 700 r/min thermal reference speed and 1,200 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3188, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3188 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 226 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5120/10000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3188-ECMA-HB1?",
        "a": "SKF NU 3188 ECMA/HB1 is a single-row caged cylindrical roller bearing with 440 mm bore, 720 mm OD and 226 mm width per ISO 15. SKF lists C 5120 kN, C0 10000 kN, Pu 765 kN, reference speed 700 r/min and limiting speed 1,200 r/min, mass about 388000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3188-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3188-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3188",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3188-ECMA-HB1",
      "SKF NU 3188 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3192-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3192 ECMA/HB1",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 460,
    "D_mm": 760,
    "B_mm": 240,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5280,
    "static_load_kN": 9650,
    "fatigue_load_limit_kN": 735,
    "max_rpm": 1100,
    "reference_speed_rpm": 670,
    "limiting_speed_rpm": 1100,
    "weight_g": 450000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU3192-ECMA-HB1 is the 460 mm bore entry in the NU3100 range: a 460×760×240 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 5280 kN / C0 9650 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 150.0 mm and the catalogue mass 450000 g; at 5280 kN dynamic rating this is roughly 11.48 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 460 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3192, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3192 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 760 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 240 mm-wide ring and concentrates load.",
      "The 5280/9650 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3192-ECMA-HB1?",
        "a": "SKF NU 3192 ECMA/HB1 is a single-row caged cylindrical roller bearing with 460 mm bore, 760 mm OD and 240 mm width per ISO 15. SKF lists C 5280 kN, C0 9650 kN, Pu 735 kN, reference speed 670 r/min and limiting speed 1,100 r/min, mass about 450000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3192-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3192-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3192",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3192-ECMA-HB1",
      "SKF NU 3192 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3196-ECMA-HB1",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3196 ECMA/HB1",
    "series": "NU3100-series",
    "type": "cylindrical_roller",
    "d_mm": 480,
    "D_mm": 790,
    "B_mm": 248,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 5940,
    "static_load_kN": 10800,
    "fatigue_load_limit_kN": 800,
    "max_rpm": 1100,
    "reference_speed_rpm": 630,
    "limiting_speed_rpm": 1100,
    "weight_g": 507000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU3196-ECMA-HB1 is the 480 mm bore entry in the NU3100 range: a 480×790×248 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 5940 kN / C0 10800 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA/HB1: the basic execution supplied with a standard pressed-steel cage. With C 5940 kN and C0 10800 kN, size the bearing on the 480×790 mm ISO 15 envelope and check the 800 kN Pu against the equivalent-load floor; the catalogue lists 630 r/min thermal reference speed and 1,100 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 480 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 31 (compact OD, wide) envelope is shared with the N/NU/NJ/NUP executions of 3196, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3196 ECMA/HB1 and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 790 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 5940/10800 kN ratings are SKF catalogue 17000 (2018) values for the ECMA/HB1 execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3196-ECMA-HB1?",
        "a": "SKF NU 3196 ECMA/HB1 is a single-row caged cylindrical roller bearing with 480 mm bore, 790 mm OD and 248 mm width per ISO 15. SKF lists C 5940 kN, C0 10800 kN, Pu 800 kN, reference speed 630 r/min and limiting speed 1,100 r/min, mass about 507000 g."
      },
      {
        "q": "What does the NU designation and ECMA/HB1 suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3196-ECMA-HB1 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3196-ECMA-HB1 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3196",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3196-ECMA-HB1",
      "SKF NU 3196 ECMA/HB1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU321-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 321 ECP",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 105,
    "D_mm": 225,
    "B_mm": 49,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 500,
    "static_load_kN": 500,
    "fatigue_load_limit_kN": 57,
    "max_rpm": 3800,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3800,
    "weight_g": 8500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 105 mm shaft, SKF lists NU321-ECP as single-row caged cylindrical roller: 225 mm OD, 49 mm wide, Pu 57 kN, the catalogue lists 3,200 r/min thermal reference speed and 3,800 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 500 kN and C0 500 kN, size the bearing on the 105×225 mm ISO 15 envelope and check the 57 kN Pu against the equivalent-load floor; the catalogue lists 3,200 r/min thermal reference speed and 3,800 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 321, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 321 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 225 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 49 mm-wide ring and concentrates load.",
      "The 500/500 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU321-ECP?",
        "a": "SKF NU 321 ECP is a single-row caged cylindrical roller bearing with 105 mm bore, 225 mm OD and 49 mm width per ISO 15. SKF lists C 500 kN, C0 500 kN, Pu 57 kN, reference speed 3,200 r/min and limiting speed 3,800 r/min, mass about 8500 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU321-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU321-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU321",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 105×225×49 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N321-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×225×49 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ321-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×225×49 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU321-ECP",
      "SKF NU 321 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU322-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 322 ECP",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 530,
    "static_load_kN": 540,
    "fatigue_load_limit_kN": 61,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 322 ECP is a single-row caged cylindrical roller bearing sized 110×240×50 mm — a dimension series 3 (medium-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NU322-ECP: the catalogue lists 3,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. The mass entry 10500 g covers the complete catalogue execution. Fit practice for NU322-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 322, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 322 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 50 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 50 mm-wide ring and concentrates load.",
      "The 530/540 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU322-ECP?",
        "a": "SKF NU 322 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 240 mm OD and 50 mm width per ISO 15. SKF lists C 530 kN, C0 540 kN, Pu 61 kN, reference speed 3,000 r/min and limiting speed 3,400 r/min, mass about 10500 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU322-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU322-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU322",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×50 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ322-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×50 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×50 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU322-ECP",
      "SKF NU 322 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU324-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 324 ECP",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 610,
    "static_load_kN": 620,
    "fatigue_load_limit_kN": 69.5,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 13000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 324 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 120×260×55 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 13000 g. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.02 (620 against 610 kN), and the Pu figure 69.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,800 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. Fit practice for NU324-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 324, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 324 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 260 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 55 mm-wide ring and concentrates load.",
      "The 610/620 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU324-ECP?",
        "a": "SKF NU 324 ECP is a single-row caged cylindrical roller bearing with 120 mm bore, 260 mm OD and 55 mm width per ISO 15. SKF lists C 610 kN, C0 620 kN, Pu 69.5 kN, reference speed 2,800 r/min and limiting speed 3,200 r/min, mass about 13000 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU324-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU324-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU324",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×260×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N324-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×55 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ324-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×55 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP324-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×55 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU324-ECP",
      "SKF NU 324 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU326-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 326 ECP",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 720,
    "static_load_kN": 750,
    "fatigue_load_limit_kN": 81.5,
    "max_rpm": 3000,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3000,
    "weight_g": 16000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 326 ECP resolves to a 130×280×58 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NU326-ECP: the catalogue lists 2,400 r/min thermal reference speed and 3,000 r/min mechanical limiting speed. The mass entry 16000 g covers the complete catalogue execution. Fit practice for NU326-ECP: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 326, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 326 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 280 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 58 mm-wide ring and concentrates load.",
      "The 720/750 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU326-ECP?",
        "a": "SKF NU 326 ECP is a single-row caged cylindrical roller bearing with 130 mm bore, 280 mm OD and 58 mm width per ISO 15. SKF lists C 720 kN, C0 750 kN, Pu 81.5 kN, reference speed 2,400 r/min and limiting speed 3,000 r/min, mass about 16000 g."
      },
      {
        "q": "What does the NU designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU326-ECP take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU326-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU326",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×280×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N326-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×58 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ326-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP326-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×58 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU326-ECP",
      "SKF NU 326 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU328-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 328 ECM",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 780,
    "static_load_kN": 830,
    "fatigue_load_limit_kN": 88,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 140 mm shaft, SKF lists NU328-ECM as single-row caged cylindrical roller: 300 mm OD, 62 mm wide, Pu 88 kN, the catalogue lists 2,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.06 (830 against 780 kN), and the Pu figure 88 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Fit practice for NU328-ECM: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 328, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 328 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 62 mm-wide ring and concentrates load.",
      "The 780/830 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU328-ECM?",
        "a": "SKF NU 328 ECM is a single-row caged cylindrical roller bearing with 140 mm bore, 300 mm OD and 62 mm width per ISO 15. SKF lists C 780 kN, C0 830 kN, Pu 88 kN, reference speed 2,400 r/min and limiting speed 2,800 r/min, mass about 22500 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU328-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU328-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU328",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×300×62 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ328-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×62 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUP328-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×62 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU328-ECM",
      "SKF NU 328 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU330-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 330 ECM",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 320,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 900,
    "static_load_kN": 965,
    "fatigue_load_limit_kN": 100,
    "max_rpm": 2600,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2600,
    "weight_g": 26500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU330-ECM is the 150 mm bore entry in the NU300 range: a 150×320×65 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 900 kN / C0 965 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 85.0 mm and the catalogue mass 26500 g; at 900 kN dynamic rating this is roughly 6.00 kN of C per millimetre of bore before application factors. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 150 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 330, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 330 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 320 mm raceway.",
      "The 900/965 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU330-ECM?",
        "a": "SKF NU 330 ECM is a single-row caged cylindrical roller bearing with 150 mm bore, 320 mm OD and 65 mm width per ISO 15. SKF lists C 900 kN, C0 965 kN, Pu 100 kN, reference speed 2,200 r/min and limiting speed 2,600 r/min, mass about 26500 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU330-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU330-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU330",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 150×320×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ330-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×320×65 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU330-ECM",
      "SKF NU 330 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU332-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 332 ECML",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1000,
    "static_load_kN": 1080,
    "fatigue_load_limit_kN": 112,
    "max_rpm": 3600,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 3600,
    "weight_g": 31000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 160 mm shaft, SKF lists NU332-ECML as single-row caged cylindrical roller: 340 mm OD, 68 mm wide, Pu 112 kN, the catalogue lists 2,000 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Speed planning for NU332-ECML: the catalogue lists 2,000 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. The mass entry 31000 g covers the complete catalogue execution. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 160 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 332, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 332 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 68 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1000/1080 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU332-ECML?",
        "a": "SKF NU 332 ECML is a single-row caged cylindrical roller bearing with 160 mm bore, 340 mm OD and 68 mm width per ISO 15. SKF lists C 1000 kN, C0 1080 kN, Pu 112 kN, reference speed 2,000 r/min and limiting speed 3,600 r/min, mass about 31000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU332-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU332-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU332",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 160×340×68 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ332-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×340×68 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU332-ECML",
      "SKF NU 332 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU334-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 334 ECM",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 360,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 952,
    "static_load_kN": 1180,
    "fatigue_load_limit_kN": 116,
    "max_rpm": 2200,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 2200,
    "weight_g": 33000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 334 ECM denotes a single-row caged cylindrical roller bearing on the ISO 15 170×360×72 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 33000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. The radial section height is 95.0 mm and the catalogue mass 33000 g; at 952 kN dynamic rating this is roughly 5.60 kN of C per millimetre of bore before application factors. Fit practice for NU334-ECM: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 334, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 334 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 72 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 360 mm raceway.",
      "The 952/1180 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU334-ECM?",
        "a": "SKF NU 334 ECM is a single-row caged cylindrical roller bearing with 170 mm bore, 360 mm OD and 72 mm width per ISO 15. SKF lists C 952 kN, C0 1180 kN, Pu 116 kN, reference speed 1,700 r/min and limiting speed 2,200 r/min, mass about 33000 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU334-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU334-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU334",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 170×360×72 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU334",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU334-ECM",
      "SKF NU 334 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU336-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 336 ECM",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 380,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1020,
    "static_load_kN": 1290,
    "fatigue_load_limit_kN": 125,
    "max_rpm": 2200,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 2200,
    "weight_g": 42500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 336 ECM resolves to a 180×380×75 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Speed planning for NU336-ECM: the catalogue lists 1,600 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. The mass entry 42500 g covers the complete catalogue execution. Fit practice for NU336-ECM: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 336, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 336 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "The 1020/1290 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU336-ECM?",
        "a": "SKF NU 336 ECM is a single-row caged cylindrical roller bearing with 180 mm bore, 380 mm OD and 75 mm width per ISO 15. SKF lists C 1020 kN, C0 1290 kN, Pu 125 kN, reference speed 1,600 r/min and limiting speed 2,200 r/min, mass about 42500 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU336-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU336-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU336",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 180×380×75 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ336-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×380×75 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU336-ECM",
      "SKF NU 336 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU338-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 338 ECM",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 400,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1140,
    "static_load_kN": 1500,
    "fatigue_load_limit_kN": 143,
    "max_rpm": 2000,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 2000,
    "weight_g": 50000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU338-ECM is the 190 mm bore entry in the NU300 range: a 190×400×78 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1140 kN / C0 1500 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.32 (1500 against 1140 kN), and the Pu figure 143 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,500 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Fit practice for NU338-ECM: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 338, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 338 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 1140/1500 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU338-ECM?",
        "a": "SKF NU 338 ECM is a single-row caged cylindrical roller bearing with 190 mm bore, 400 mm OD and 78 mm width per ISO 15. SKF lists C 1140 kN, C0 1500 kN, Pu 143 kN, reference speed 1,500 r/min and limiting speed 2,000 r/min, mass about 50000 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU338-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU338-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU338",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 190×400×78 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU338",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU338-ECM",
      "SKF NU 338 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU340-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 340 ECML",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 420,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1230,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 150,
    "max_rpm": 2800,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 2800,
    "weight_g": 57000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 340 ECML is a single-row caged cylindrical roller bearing sized 200×420×80 mm — a dimension series 3 (medium-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Speed planning for NU340-ECML: the catalogue lists 1,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. The mass entry 57000 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 340, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 340 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 420 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 420 mm raceway.",
      "The 1230/1630 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU340-ECML?",
        "a": "SKF NU 340 ECML is a single-row caged cylindrical roller bearing with 200 mm bore, 420 mm OD and 80 mm width per ISO 15. SKF lists C 1230 kN, C0 1630 kN, Pu 150 kN, reference speed 1,400 r/min and limiting speed 2,800 r/min, mass about 57000 g."
      },
      {
        "q": "What does the NU designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU340-ECML take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU340-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU340",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 200×420×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ340-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×420×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU340-ECML",
      "SKF NU 340 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU344-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 344 M",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 460,
    "B_mm": 88,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1210,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 150,
    "max_rpm": 1700,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 1700,
    "weight_g": 75000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 220 mm shaft, SKF lists NU344-M as single-row caged cylindrical roller: 460 mm OD, 88 mm wide, Pu 150 kN, the catalogue lists 1,500 r/min thermal reference speed and 1,700 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix M: the basic (non-E) M execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 120.0 mm and the catalogue mass 75000 g; at 1210 kN dynamic rating this is roughly 5.50 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 344, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 344 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 460 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 88 mm-wide ring and concentrates load.",
      "The 1210/1630 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU344-M?",
        "a": "SKF NU 344 M is a single-row caged cylindrical roller bearing with 220 mm bore, 460 mm OD and 88 mm width per ISO 15. SKF lists C 1210 kN, C0 1630 kN, Pu 150 kN, reference speed 1,500 r/min and limiting speed 1,700 r/min, mass about 75000 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU344-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU344-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU344",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ344-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×460×88 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU344-M",
      "SKF NU 344 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU348-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 348 MA",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 500,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1450,
    "static_load_kN": 2000,
    "fatigue_load_limit_kN": 180,
    "max_rpm": 2000,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 2000,
    "weight_g": 94500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 348 MA is a single-row caged cylindrical roller bearing sized 240×500×95 mm — a dimension series 3 (medium-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 130.0 mm and the catalogue mass 94500 g; at 1450 kN dynamic rating this is roughly 6.04 kN of C per millimetre of bore before application factors. Fit practice for NU348-MA: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 348, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 348 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 95 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 500 mm raceway.",
      "The 1450/2000 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU348-MA?",
        "a": "SKF NU 348 MA is a single-row caged cylindrical roller bearing with 240 mm bore, 500 mm OD and 95 mm width per ISO 15. SKF lists C 1450 kN, C0 2000 kN, Pu 180 kN, reference speed 1,300 r/min and limiting speed 2,000 r/min, mass about 94500 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU348-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU348-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU348",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ348-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 240×500×95 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU348-MA",
      "SKF NU 348 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU352-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 352 ECMA",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 260,
    "D_mm": 540,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1940,
    "static_load_kN": 2700,
    "fatigue_load_limit_kN": 236,
    "max_rpm": 1800,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1800,
    "weight_g": 121000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU352-ECMA is the 260 mm bore entry in the NU300 range: a 260×540×102 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1940 kN / C0 2700 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1940 kN and C0 2700 kN, size the bearing on the 260×540 mm ISO 15 envelope and check the 236 kN Pu against the equivalent-load floor; the catalogue lists 1,100 r/min thermal reference speed and 1,800 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 260 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 352, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 352 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1940/2700 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU352-ECMA?",
        "a": "SKF NU 352 ECMA is a single-row caged cylindrical roller bearing with 260 mm bore, 540 mm OD and 102 mm width per ISO 15. SKF lists C 1940 kN, C0 2700 kN, Pu 236 kN, reference speed 1,100 r/min and limiting speed 1,800 r/min, mass about 121000 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU352-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU352-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU352",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 260×540×102 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NU352",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU352-ECMA",
      "SKF NU 352 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU360-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 360 ECM",
    "series": "NU300-series",
    "type": "cylindrical_roller",
    "d_mm": 300,
    "D_mm": 620,
    "B_mm": 109,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2330,
    "static_load_kN": 3350,
    "fatigue_load_limit_kN": 280,
    "max_rpm": 1200,
    "reference_speed_rpm": 950,
    "limiting_speed_rpm": 1200,
    "weight_g": 174000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 300 mm shaft, SKF lists NU360-ECM as single-row caged cylindrical roller: 620 mm OD, 109 mm wide, Pu 280 kN, the catalogue lists 950 r/min thermal reference speed and 1,200 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.44 (3350 against 2330 kN), and the Pu figure 280 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 950 r/min thermal reference speed and 1,200 r/min mechanical limiting speed. Fit practice for NU360-ECM: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 360, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 360 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 109 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 109 mm-wide ring and concentrates load.",
      "The 2330/3350 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU360-ECM?",
        "a": "SKF NU 360 ECM is a single-row caged cylindrical roller bearing with 300 mm bore, 620 mm OD and 109 mm width per ISO 15. SKF lists C 2330 kN, C0 3350 kN, Pu 280 kN, reference speed 950 r/min and limiting speed 1,200 r/min, mass about 174000 g."
      },
      {
        "q": "What does the NU designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU360-ECM take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU360-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU360",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU360-ECM",
      "SKF NU 360 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU3980-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 3980 ECMA",
    "series": "NU3900-series",
    "type": "cylindrical_roller",
    "d_mm": 400,
    "D_mm": 540,
    "B_mm": 106,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1760,
    "static_load_kN": 3750,
    "fatigue_load_limit_kN": 320,
    "max_rpm": 1500,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1500,
    "weight_g": 74500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU3980-ECMA is the 400 mm bore entry in the NU3900 range: a 400×540×106 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1760 kN / C0 3750 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Speed planning for NU3980-ECMA: the catalogue lists 1,000 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. The mass entry 74500 g covers the complete catalogue execution. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 400 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 39 (compact OD) envelope is shared with the N/NU/NJ/NUP executions of 3980, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 3980 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 540 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 106 mm-wide ring and concentrates load.",
      "The 1760/3750 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU3980-ECMA?",
        "a": "SKF NU 3980 ECMA is a single-row caged cylindrical roller bearing with 400 mm bore, 540 mm OD and 106 mm width per ISO 15. SKF lists C 1760 kN, C0 3750 kN, Pu 320 kN, reference speed 1,000 r/min and limiting speed 1,500 r/min, mass about 74500 g."
      },
      {
        "q": "What does the NU designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU3980-ECMA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU3980-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU3980",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU3980-ECMA",
      "SKF NU 3980 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU406-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 406 MA",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 30,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 53,
    "fatigue_load_limit_kN": 6.8,
    "max_rpm": 11000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 11000,
    "weight_g": 750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 30 mm shaft, SKF lists NU406-MA as single-row caged cylindrical roller: 90 mm OD, 23 mm wide, Pu 6.8 kN, the catalogue lists 9,000 r/min thermal reference speed and 11,000 r/min mechanical limiting speed. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 60.5 kN and C0 53 kN, size the bearing on the 30×90 mm ISO 15 envelope and check the 6.8 kN Pu against the equivalent-load floor; the catalogue lists 9,000 r/min thermal reference speed and 11,000 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 30 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 406, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 406 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 90 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 23 mm-wide ring and concentrates load.",
      "The 60.5/53 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU406-MA?",
        "a": "SKF NU 406 MA is a single-row caged cylindrical roller bearing with 30 mm bore, 90 mm OD and 23 mm width per ISO 15. SKF lists C 60.5 kN, C0 53 kN, Pu 6.8 kN, reference speed 9,000 r/min and limiting speed 11,000 r/min, mass about 750 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU406-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU406-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU406",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 30×90×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ406-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×90×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU406-MA",
      "SKF NU 406 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU407",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 407",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 35,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 69.5,
    "fatigue_load_limit_kN": 9,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 1000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU407 is the 35 mm bore entry in the NU400 range: a 35×100×25 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 76.5 kN / C0 69.5 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. With C 76.5 kN and C0 69.5 kN, size the bearing on the 35×100 mm ISO 15 envelope and check the 9 kN Pu against the equivalent-load floor; the catalogue lists 8,000 r/min thermal reference speed and 9,500 r/min mechanical limiting speed. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 407, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 407 and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 76.5/69.5 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU407?",
        "a": "SKF NU 407 is a single-row caged cylindrical roller bearing with 35 mm bore, 100 mm OD and 25 mm width per ISO 15. SKF lists C 76.5 kN, C0 69.5 kN, Pu 9 kN, reference speed 8,000 r/min and limiting speed 9,500 r/min, mass about 1000 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU407 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU407 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU407-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ407",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×100×25 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU407",
      "SKF NU 407"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU408-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 408 M",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 40,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 96.8,
    "static_load_kN": 90,
    "fatigue_load_limit_kN": 11.6,
    "max_rpm": 8500,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8500,
    "weight_g": 1300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU408-M is the 40 mm bore entry in the NU400 range: a 40×110×27 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 96.8 kN / C0 90 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix M: the basic (non-E) M execution with a machined brass cage, standard for the larger and earlier-design sizes. Selection arithmetic: C0/C ≈ 0.93 (90 against 96.8 kN), and the Pu figure 11.6 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 7,000 r/min thermal reference speed and 8,500 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 40 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 408, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 408 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 96.8/90 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU408-M?",
        "a": "SKF NU 408 M is a single-row caged cylindrical roller bearing with 40 mm bore, 110 mm OD and 27 mm width per ISO 15. SKF lists C 96.8 kN, C0 90 kN, Pu 11.6 kN, reference speed 7,000 r/min and limiting speed 8,500 r/min, mass about 1300 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU408-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU408-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU408",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ408-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×110×27 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU408-M",
      "SKF NU 408 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU409",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 409",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 45,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 106,
    "static_load_kN": 102,
    "fatigue_load_limit_kN": 13.4,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 1650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 45 mm shaft, SKF lists NU409 as single-row caged cylindrical roller: 120 mm OD, 29 mm wide, Pu 13.4 kN, the catalogue lists 6,700 r/min thermal reference speed and 7,500 r/min mechanical limiting speed. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. With C 106 kN and C0 102 kN, size the bearing on the 45×120 mm ISO 15 envelope and check the 13.4 kN Pu against the equivalent-load floor; the catalogue lists 6,700 r/min thermal reference speed and 7,500 r/min mechanical limiting speed. Fit practice for NU409: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 409, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 409 and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 29 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 29 mm-wide ring and concentrates load.",
      "The 106/102 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU409?",
        "a": "SKF NU 409 is a single-row caged cylindrical roller bearing with 45 mm bore, 120 mm OD and 29 mm width per ISO 15. SKF lists C 106 kN, C0 102 kN, Pu 13.4 kN, reference speed 6,700 r/min and limiting speed 7,500 r/min, mass about 1650 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU409 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU409 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU409-NTN",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 45×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ409",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×120×29 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU409",
      "SKF NU 409"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU410",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 410",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 50,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 130,
    "static_load_kN": 127,
    "fatigue_load_limit_kN": 16.6,
    "max_rpm": 7000,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 7000,
    "weight_g": 2000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 410 is a single-row caged cylindrical roller bearing sized 50×130×31 mm — a dimension series 4 (heavy-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 50 mm seat is about 2.60 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 127 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 410, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 410 and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 130/127 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU410?",
        "a": "SKF NU 410 is a single-row caged cylindrical roller bearing with 50 mm bore, 130 mm OD and 31 mm width per ISO 15. SKF lists C 130 kN, C0 127 kN, Pu 16.6 kN, reference speed 6,000 r/min and limiting speed 7,000 r/min, mass about 2000 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU410 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU410 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU410-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ410",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×130×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU410",
      "SKF NU 410"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU411",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 411",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 55,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 142,
    "static_load_kN": 140,
    "fatigue_load_limit_kN": 18.6,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 2500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU411 is the 55 mm bore entry in the NU400 range: a 55×140×33 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 142 kN / C0 140 kN. The NU configuration means two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 55 mm seat is about 2.58 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 140 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 55 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 411, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 411 and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 140 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 140 mm raceway.",
      "The 142/140 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU411?",
        "a": "SKF NU 411 is a single-row caged cylindrical roller bearing with 55 mm bore, 140 mm OD and 33 mm width per ISO 15. SKF lists C 142 kN, C0 140 kN, Pu 18.6 kN, reference speed 5,600 r/min and limiting speed 6,300 r/min, mass about 2500 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU411 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU411 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU411-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ411",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×140×33 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU411",
      "SKF NU 411"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU412",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 412",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 60,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 168,
    "static_load_kN": 173,
    "fatigue_load_limit_kN": 22,
    "max_rpm": 6000,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 6000,
    "weight_g": 3000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NU 412 denotes a single-row caged cylindrical roller bearing on the ISO 15 60×150×35 mm envelope, dimension series 4 (heavy-section ISO 15 envelope), with catalogue mass 3000 g. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 60 mm seat is about 2.80 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 173 kN for static checks such as crane hook blocks standing under load. Fit practice for NU412: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 412, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 412 and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 35 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 35 mm-wide ring and concentrates load.",
      "The 168/173 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU412?",
        "a": "SKF NU 412 is a single-row caged cylindrical roller bearing with 60 mm bore, 150 mm OD and 35 mm width per ISO 15. SKF lists C 168 kN, C0 173 kN, Pu 22 kN, reference speed 5,000 r/min and limiting speed 6,000 r/min, mass about 3000 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU412 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU412 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU412-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ412",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×150×35 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU412",
      "SKF NU 412"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU413",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 413",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 160,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 183,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 24,
    "max_rpm": 5600,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5600,
    "weight_g": 3550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 65 mm shaft, SKF lists NU413 as single-row caged cylindrical roller: 160 mm OD, 37 mm wide, Pu 24 kN, the catalogue lists 4,800 r/min thermal reference speed and 5,600 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 65 mm seat is about 2.82 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 190 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 413, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 413 and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 183/190 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU413?",
        "a": "SKF NU 413 is a single-row caged cylindrical roller bearing with 65 mm bore, 160 mm OD and 37 mm width per ISO 15. SKF lists C 183 kN, C0 190 kN, Pu 24 kN, reference speed 4,800 r/min and limiting speed 5,600 r/min, mass about 3550 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU413 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU413 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU413-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ413",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×160×37 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU413",
      "SKF NU 413"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU414-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 414 MA",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 180,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 229,
    "static_load_kN": 240,
    "fatigue_load_limit_kN": 30,
    "max_rpm": 5000,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 5000,
    "weight_g": 5250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU414-MA is the 70 mm bore entry in the NU400 range: a 70×180×42 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 229 kN / C0 240 kN. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. Load-per-bore for the 70 mm seat is about 3.27 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 240 kN for static checks such as crane hook blocks standing under load. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 70 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 414, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 414 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 42 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 229/240 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU414-MA?",
        "a": "SKF NU 414 MA is a single-row caged cylindrical roller bearing with 70 mm bore, 180 mm OD and 42 mm width per ISO 15. SKF lists C 229 kN, C0 240 kN, Pu 30 kN, reference speed 4,300 r/min and limiting speed 5,000 r/min, mass about 5250 g."
      },
      {
        "q": "What does the NU designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU414-MA take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU414-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU414",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ414-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×180×42 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU414-MA",
      "SKF NU 414 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU415",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 415",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 190,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 264,
    "static_load_kN": 280,
    "fatigue_load_limit_kN": 34,
    "max_rpm": 4800,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4800,
    "weight_g": 6200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 415 is a single-row caged cylindrical roller bearing sized 75×190×45 mm — a dimension series 4 (heavy-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 75 mm seat is about 3.52 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 280 kN for static checks such as crane hook blocks standing under load. Fit practice for NU415: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 415, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 415 and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 45 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 45 mm-wide ring and concentrates load.",
      "The 264/280 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU415?",
        "a": "SKF NU 415 is a single-row caged cylindrical roller bearing with 75 mm bore, 190 mm OD and 45 mm width per ISO 15. SKF lists C 264 kN, C0 280 kN, Pu 34 kN, reference speed 4,000 r/min and limiting speed 4,800 r/min, mass about 6200 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU415 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU415 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU415-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ415",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×190×45 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU415",
      "SKF NU 415"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU416",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 416",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 200,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 303,
    "static_load_kN": 320,
    "fatigue_load_limit_kN": 39,
    "max_rpm": 4500,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4500,
    "weight_g": 7250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU416 is the 80 mm bore entry in the NU400 range: a 80×200×48 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 303 kN / C0 320 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 80 mm seat is about 3.79 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 320 kN for static checks such as crane hook blocks standing under load. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 416, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 416 and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 303/320 kN ratings are SKF catalogue 17000 (2018) values for the basic execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU416?",
        "a": "SKF NU 416 is a single-row caged cylindrical roller bearing with 80 mm bore, 200 mm OD and 48 mm width per ISO 15. SKF lists C 303 kN, C0 320 kN, Pu 39 kN, reference speed 3,800 r/min and limiting speed 4,500 r/min, mass about 7250 g."
      },
      {
        "q": "What does the NU designation and plain suffix mean?",
        "a": "The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU416 take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU416 compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU416-NTN",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ416",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×200×48 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU416",
      "SKF NU 416"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU418-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 418 M",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 225,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 380,
    "static_load_kN": 415,
    "fatigue_load_limit_kN": 48,
    "max_rpm": 4000,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 4000,
    "weight_g": 10000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 90 mm shaft, SKF lists NU418-M as single-row caged cylindrical roller: 225 mm OD, 54 mm wide, Pu 48 kN, the catalogue lists 3,400 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Speed planning for NU418-M: the catalogue lists 3,400 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. The mass entry 10000 g covers the complete catalogue execution. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 418, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 418 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 380/415 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU418-M?",
        "a": "SKF NU 418 M is a single-row caged cylindrical roller bearing with 90 mm bore, 225 mm OD and 54 mm width per ISO 15. SKF lists C 380 kN, C0 415 kN, Pu 48 kN, reference speed 3,400 r/min and limiting speed 4,000 r/min, mass about 10000 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU418-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU418-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU418",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU418-M",
      "SKF NU 418 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU419-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 419 M",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 240,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 413,
    "static_load_kN": 455,
    "fatigue_load_limit_kN": 52,
    "max_rpm": 3600,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3600,
    "weight_g": 13500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NU 419 M resolves to a 95×240×55 mm single-row caged cylindrical roller bearing (dimension series 4 (heavy-section ISO 15 envelope)); two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix M: the basic (non-E) M execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 72.5 mm and the catalogue mass 13500 g; at 413 kN dynamic rating this is roughly 4.35 kN of C per millimetre of bore before application factors. Assembly note: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 419, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 419 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 55 mm-wide ring and concentrates load.",
      "The 413/455 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU419-M?",
        "a": "SKF NU 419 M is a single-row caged cylindrical roller bearing with 95 mm bore, 240 mm OD and 55 mm width per ISO 15. SKF lists C 413 kN, C0 455 kN, Pu 52 kN, reference speed 3,200 r/min and limiting speed 3,600 r/min, mass about 13500 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU419-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU419-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU419",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU419-M",
      "SKF NU 419 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU420-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 420 M",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 250,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 457,
    "static_load_kN": 520,
    "fatigue_load_limit_kN": 58.5,
    "max_rpm": 3600,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3600,
    "weight_g": 15500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NU 420 M is a single-row caged cylindrical roller bearing sized 100×250×58 mm — a dimension series 4 (heavy-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix M: the basic (non-E) M execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 75.0 mm and the catalogue mass 15500 g; at 457 kN dynamic rating this is roughly 4.57 kN of C per millimetre of bore before application factors. Fit practice for NU420-M: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 420, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 420 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 250 mm raceway.",
      "The 457/520 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU420-M?",
        "a": "SKF NU 420 M is a single-row caged cylindrical roller bearing with 100 mm bore, 250 mm OD and 58 mm width per ISO 15. SKF lists C 457 kN, C0 520 kN, Pu 58.5 kN, reference speed 3,000 r/min and limiting speed 3,600 r/min, mass about 15500 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU420-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU420-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU420",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU420-M",
      "SKF NU 420 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU421-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 421 M",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 105,
    "D_mm": 260,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 501,
    "static_load_kN": 570,
    "fatigue_load_limit_kN": 64,
    "max_rpm": 3400,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3400,
    "weight_g": 17500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 105 mm shaft, SKF lists NU421-M as single-row caged cylindrical roller: 260 mm OD, 60 mm wide, Pu 64 kN, the catalogue lists 2,800 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.14 (570 against 501 kN), and the Pu figure 64 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,800 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Mounting: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. A 105 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 421, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 421 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 60 mm-wide ring and concentrates load.",
      "The 501/570 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU421-M?",
        "a": "SKF NU 421 M is a single-row caged cylindrical roller bearing with 105 mm bore, 260 mm OD and 60 mm width per ISO 15. SKF lists C 501 kN, C0 570 kN, Pu 64 kN, reference speed 2,800 r/min and limiting speed 3,400 r/min, mass about 17500 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU421-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU421-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU421",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU421-M",
      "SKF NU 421 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NU424-M",
    "brand": "SKF",
    "manufacturer_designation": "SKF NU 424 M",
    "series": "NU400-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 310,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 644,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 78,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 27500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NU424-M is the 120 mm bore entry in the NU400 range: a 120×310×72 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 644 kN / C0 735 kN. Structurally, the NU design has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. In arrangement terms it is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix M: the basic (non-E) M execution with a machined brass cage, standard for the larger and earlier-design sizes. Speed planning for NU424-M: the catalogue lists 2,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. The mass entry 27500 g covers the complete catalogue execution. Fit practice for NU424-M: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NU bearing where axial load must be carried — the design carries radial load only",
      "The dimension series 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 424, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 424 M and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 310 mm raceway.",
      "The 644/735 kN ratings are SKF catalogue 17000 (2018) values for the M execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NU424-M?",
        "a": "SKF NU 424 M is a single-row caged cylindrical roller bearing with 120 mm bore, 310 mm OD and 72 mm width per ISO 15. SKF lists C 644 kN, C0 735 kN, Pu 78 kN, reference speed 2,400 r/min and limiting speed 2,800 r/min, mass about 27500 g."
      },
      {
        "q": "What does the NU designation and M suffix mean?",
        "a": "The M suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable."
      },
      {
        "q": "Can NU424-M take axial load and locate the shaft?",
        "a": "No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty."
      },
      {
        "q": "How does NU424-M compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NU424",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NU424-M",
      "SKF NU 424 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2220-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2220 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 400,
    "static_load_kN": 475,
    "fatigue_load_limit_kN": 57,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 5100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2220 ECMH resolves to a 100×180×46 mm high-capacity cylindrical roller bearing (dimension series 22 (light-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Speed planning for NUH2220-ECMH: the catalogue lists 4,000 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. The mass entry 5100 g covers the complete catalogue execution. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 100 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "wind-turbine rotor pinion shafts",
      "heavy mining and cement gear drives",
      "wind turbine gearbox planetary and intermediate shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2220 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "The 400/475 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2220-ECMH?",
        "a": "SKF NUH 2220 ECMH is a high-capacity cylindrical roller bearing with 100 mm bore, 180 mm OD and 46 mm width per ISO 15. SKF lists C 400 kN, C0 475 kN, Pu 57 kN, reference speed 4,000 r/min and limiting speed 4,500 r/min, mass about 5100 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2220-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2220-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2220",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2220-ECMH",
      "SKF NUH 2220 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2222-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2222 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 465,
    "static_load_kN": 550,
    "fatigue_load_limit_kN": 64,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 7300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2222 ECMH is a high-capacity cylindrical roller bearing sized 110×200×53 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.18 (550 against 465 kN), and the Pu figure 64 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,600 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Fit practice for NUH2222-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "heavy mining and cement gear drives",
      "wind turbine gearbox planetary and intermediate shafts",
      "wind-turbine rotor pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2222 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 53 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 465/550 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2222-ECMH?",
        "a": "SKF NUH 2222 ECMH is a high-capacity cylindrical roller bearing with 110 mm bore, 200 mm OD and 53 mm width per ISO 15. SKF lists C 465 kN, C0 550 kN, Pu 64 kN, reference speed 3,600 r/min and limiting speed 4,000 r/min, mass about 7300 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2222-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2222-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2222",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2222-ECMH",
      "SKF NUH 2222 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2224-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2224 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 550,
    "static_load_kN": 670,
    "fatigue_load_limit_kN": 76.5,
    "max_rpm": 3600,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3600,
    "weight_g": 9000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2224 ECMH resolves to a 120×215×58 mm high-capacity cylindrical roller bearing (dimension series 22 (light-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). With C 550 kN and C0 670 kN, size the bearing on the 120×215 mm ISO 15 envelope and check the 76.5 kN Pu against the equivalent-load floor; the catalogue lists 3,400 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. Fit practice for NUH2224-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2224 using the /PEX loads.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "The 550/670 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2224-ECMH?",
        "a": "SKF NUH 2224 ECMH is a high-capacity cylindrical roller bearing with 120 mm bore, 215 mm OD and 58 mm width per ISO 15. SKF lists C 550 kN, C0 670 kN, Pu 76.5 kN, reference speed 3,400 r/min and limiting speed 3,600 r/min, mass about 9000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2224-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2224-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2224",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2224-ECMH",
      "SKF NUH 2224 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2226-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2226 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 630,
    "static_load_kN": 780,
    "fatigue_load_limit_kN": 88,
    "max_rpm": 3400,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3400,
    "weight_g": 11000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 130 mm shaft, SKF lists NUH2226-ECMH as high-capacity cylindrical roller: 230 mm OD, 64 mm wide, Pu 88 kN, the catalogue lists 3,200 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Speed planning for NUH2226-ECMH: the catalogue lists 3,200 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. The mass entry 11000 g covers the complete catalogue execution. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 130 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2226 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 230 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 64 mm-wide ring and concentrates load.",
      "The 630/780 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2226-ECMH?",
        "a": "SKF NUH 2226 ECMH is a high-capacity cylindrical roller bearing with 130 mm bore, 230 mm OD and 64 mm width per ISO 15. SKF lists C 630 kN, C0 780 kN, Pu 88 kN, reference speed 3,200 r/min and limiting speed 3,400 r/min, mass about 11000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2226-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2226-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2226",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2226-ECMH",
      "SKF NUH 2226 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2228-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2228 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 680,
    "static_load_kN": 880,
    "fatigue_load_limit_kN": 96.5,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 14500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2228 ECMH resolves to a 140×250×68 mm high-capacity cylindrical roller bearing (dimension series 22 (light-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Selection arithmetic: C0/C ≈ 1.29 (880 against 680 kN), and the Pu figure 96.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,800 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. Fit practice for NUH2228-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2228 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 68 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 68 mm-wide ring and concentrates load.",
      "The 680/880 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2228-ECMH?",
        "a": "SKF NUH 2228 ECMH is a high-capacity cylindrical roller bearing with 140 mm bore, 250 mm OD and 68 mm width per ISO 15. SKF lists C 680 kN, C0 880 kN, Pu 96.5 kN, reference speed 2,800 r/min and limiting speed 3,200 r/min, mass about 14500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2228-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2228-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2228-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×68 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2228-ECMH",
      "SKF NUH 2228 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2230-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2230 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 780,
    "static_load_kN": 1040,
    "fatigue_load_limit_kN": 112,
    "max_rpm": 2800,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 2800,
    "weight_g": 18000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUH 2230 ECMH denotes a high-capacity cylindrical roller bearing on the ISO 15 150×270×73 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 18000 g. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.33 (1040 against 780 kN), and the Pu figure 112 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,600 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 150 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2230 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 270 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 73 mm-wide ring and concentrates load.",
      "The 780/1040 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2230-ECMH?",
        "a": "SKF NUH 2230 ECMH is a high-capacity cylindrical roller bearing with 150 mm bore, 270 mm OD and 73 mm width per ISO 15. SKF lists C 780 kN, C0 1040 kN, Pu 112 kN, reference speed 2,600 r/min and limiting speed 2,800 r/min, mass about 18000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2230-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2230-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2230-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×270×73 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2230-ECMH",
      "SKF NUH 2230 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2232-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2232 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 980,
    "static_load_kN": 1270,
    "fatigue_load_limit_kN": 134,
    "max_rpm": 2600,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2600,
    "weight_g": 23000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2232-ECMH is the 160 mm bore entry in the NUH2200 range: a 160×290×80 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 980 kN / C0 1270 kN. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 980 kN and C0 1270 kN, size the bearing on the 160×290 mm ISO 15 envelope and check the 134 kN Pu against the equivalent-load floor; the catalogue lists 2,400 r/min thermal reference speed and 2,600 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 160 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2232 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 980/1270 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2232-ECMH?",
        "a": "SKF NUH 2232 ECMH is a high-capacity cylindrical roller bearing with 160 mm bore, 290 mm OD and 80 mm width per ISO 15. SKF lists C 980 kN, C0 1270 kN, Pu 134 kN, reference speed 2,400 r/min and limiting speed 2,600 r/min, mass about 23000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2232-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2232-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2232-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×290×80 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2232-ECMH",
      "SKF NUH 2232 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2234-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2234 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1600,
    "static_load_kN": 1530,
    "fatigue_load_limit_kN": 156,
    "max_rpm": 2400,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2400,
    "weight_g": 28500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUH 2234 ECMH denotes a high-capacity cylindrical roller bearing on the ISO 15 170×310×86 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 28500 g. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Speed planning for NUH2234-ECMH: the catalogue lists 2,200 r/min thermal reference speed and 2,400 r/min mechanical limiting speed. The mass entry 28500 g covers the complete catalogue execution. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 170 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2234 using the /PEX loads.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1600/1530 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2234-ECMH?",
        "a": "SKF NUH 2234 ECMH is a high-capacity cylindrical roller bearing with 170 mm bore, 310 mm OD and 86 mm width per ISO 15. SKF lists C 1600 kN, C0 1530 kN, Pu 156 kN, reference speed 2,200 r/min and limiting speed 2,400 r/min, mass about 28500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2234-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2234-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2234-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 170×310×86 mm, but catalogue C/C0 ratings differ between executions (1600/1530 vs 1160/1530 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2234-ECMH",
      "SKF NUH 2234 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2236-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2236 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1200,
    "static_load_kN": 1600,
    "fatigue_load_limit_kN": 166,
    "max_rpm": 2400,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2400,
    "weight_g": 29500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2236-ECMH is the 180 mm bore entry in the NUH2200 range: a 180×320×86 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 1200 kN / C0 1600 kN. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.33 (1600 against 1200 kN), and the Pu figure 166 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,200 r/min thermal reference speed and 2,400 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 180 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2236 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 320 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1200/1600 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2236-ECMH?",
        "a": "SKF NUH 2236 ECMH is a high-capacity cylindrical roller bearing with 180 mm bore, 320 mm OD and 86 mm width per ISO 15. SKF lists C 1200 kN, C0 1600 kN, Pu 166 kN, reference speed 2,200 r/min and limiting speed 2,400 r/min, mass about 29500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2236-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2236-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2236-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×320×86 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2236-ECMH",
      "SKF NUH 2236 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2238-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2238 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1320,
    "static_load_kN": 1760,
    "fatigue_load_limit_kN": 180,
    "max_rpm": 2200,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2200,
    "weight_g": 36000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2238 ECMH is a high-capacity cylindrical roller bearing sized 190×340×92 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). With C 1320 kN and C0 1760 kN, size the bearing on the 190×340 mm ISO 15 envelope and check the 180 kN Pu against the equivalent-load floor; the catalogue lists 2,000 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 190 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2238 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 92 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1320/1760 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2238-ECMH?",
        "a": "SKF NUH 2238 ECMH is a high-capacity cylindrical roller bearing with 190 mm bore, 340 mm OD and 92 mm width per ISO 15. SKF lists C 1320 kN, C0 1760 kN, Pu 180 kN, reference speed 2,000 r/min and limiting speed 2,200 r/min, mass about 36000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2238-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2238-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2238-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×340×92 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2238-ECMH",
      "SKF NUH 2238 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2240-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2240 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 98,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1460,
    "static_load_kN": 2000,
    "fatigue_load_limit_kN": 200,
    "max_rpm": 2200,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2200,
    "weight_g": 43500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2240 ECMH is a high-capacity cylindrical roller bearing sized 200×360×98 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). With C 1460 kN and C0 2000 kN, size the bearing on the 200×360 mm ISO 15 envelope and check the 200 kN Pu against the equivalent-load floor; the catalogue lists 1,900 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 200 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2240 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 360 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1460/2000 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2240-ECMH?",
        "a": "SKF NUH 2240 ECMH is a high-capacity cylindrical roller bearing with 200 mm bore, 360 mm OD and 98 mm width per ISO 15. SKF lists C 1460 kN, C0 2000 kN, Pu 200 kN, reference speed 1,900 r/min and limiting speed 2,200 r/min, mass about 43500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2240-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2240-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2240-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×360×98 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2240-ECMH",
      "SKF NUH 2240 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2244-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2244 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 400,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1760,
    "static_load_kN": 2600,
    "fatigue_load_limit_kN": 240,
    "max_rpm": 1900,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 1900,
    "weight_g": 59000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 220 mm shaft, SKF lists NUH2244-ECMH as high-capacity cylindrical roller: 400 mm OD, 108 mm wide, Pu 240 kN, the catalogue lists 1,600 r/min thermal reference speed and 1,900 r/min mechanical limiting speed. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.48 (2600 against 1760 kN), and the Pu figure 240 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 1,900 r/min mechanical limiting speed. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2244 using the /PEX loads.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 1760/2600 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2244-ECMH?",
        "a": "SKF NUH 2244 ECMH is a high-capacity cylindrical roller bearing with 220 mm bore, 400 mm OD and 108 mm width per ISO 15. SKF lists C 1760 kN, C0 2600 kN, Pu 240 kN, reference speed 1,600 r/min and limiting speed 1,900 r/min, mass about 59000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2244-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2244-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2244-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×108 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NCF2244-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×400×108 mm, but catalogue C/C0 ratings differ between executions (1760/2600 vs 2000/2600 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2244-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×400×108 mm, but catalogue C/C0 ratings differ between executions (1760/2600 vs 2000/2600 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2244-ECMH",
      "SKF NUH 2244 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2244-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2244 ECMH/PEX",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 400,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2000,
    "static_load_kN": 2600,
    "fatigue_load_limit_kN": 240,
    "max_rpm": 1900,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 1900,
    "weight_g": 59000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2244-ECMH-PEX is the 220 mm bore entry in the NUH2200 range: a 220×400×108 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 2000 kN / C0 2600 kN. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Speed planning for NUH2244-ECMH-PEX: the catalogue lists 1,700 r/min thermal reference speed and 1,900 r/min mechanical limiting speed. The mass entry 59000 g covers the complete catalogue execution. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 220 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 2000 kN / C0 2600 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2244-ECMH-PEX as a separate service part: do not substitute the standard NUH 2244 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2244 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 108 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 2000/2600 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2244-ECMH-PEX?",
        "a": "SKF NUH 2244 ECMH/PEX is a high-capacity cylindrical roller bearing with 220 mm bore, 400 mm OD and 108 mm width per ISO 15. SKF lists C 2000 kN, C0 2600 kN, Pu 240 kN, reference speed 1,700 r/min and limiting speed 1,900 r/min, mass about 59000 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2244-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2244-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2244-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×400×108 mm, but catalogue C/C0 ratings differ between executions (2000/2600 vs 1760/2600 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NCF2244-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×108 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2244-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×400×108 mm, but catalogue C/C0 ratings differ between executions (2000/2600 vs 1760/2600 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2244-ECMH-PEX",
      "SKF NUH 2244 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2248-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2248 ECMH",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1980,
    "static_load_kN": 3050,
    "fatigue_load_limit_kN": 275,
    "max_rpm": 1700,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 1700,
    "weight_g": 80000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 240 mm shaft, SKF lists NUH2248-ECMH as high-capacity cylindrical roller: 440 mm OD, 120 mm wide, Pu 275 kN, the catalogue lists 1,400 r/min thermal reference speed and 1,700 r/min mechanical limiting speed. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Speed planning for NUH2248-ECMH: the catalogue lists 1,400 r/min thermal reference speed and 1,700 r/min mechanical limiting speed. The mass entry 80000 g covers the complete catalogue execution. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2248 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 120 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 120 mm-wide ring and concentrates load.",
      "The 1980/3050 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2248-ECMH?",
        "a": "SKF NUH 2248 ECMH is a high-capacity cylindrical roller bearing with 240 mm bore, 440 mm OD and 120 mm width per ISO 15. SKF lists C 1980 kN, C0 3050 kN, Pu 275 kN, reference speed 1,400 r/min and limiting speed 1,700 r/min, mass about 80000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2248-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2248-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2248-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 240×440×120 mm, but catalogue C/C0 ratings differ between executions (1980/3050 vs 2279/3050 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2248-ECMH",
      "SKF NUH 2248 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2248-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2248 ECMH/PEX",
    "series": "NUH2200-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2279,
    "static_load_kN": 3050,
    "fatigue_load_limit_kN": 275,
    "max_rpm": 1700,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 1700,
    "weight_g": 80000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2248-ECMH-PEX is the 240 mm bore entry in the NUH2200 range: a 240×440×120 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 2279 kN / C0 3050 kN. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.34 (3050 against 2279 kN), and the Pu figure 275 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 1,700 r/min mechanical limiting speed. Fit practice for NUH2248-ECMH-PEX: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 2279 kN / C0 3050 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2248-ECMH-PEX as a separate service part: do not substitute the standard NUH 2248 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2248 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 120 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 440 mm raceway.",
      "The 2279/3050 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2248-ECMH-PEX?",
        "a": "SKF NUH 2248 ECMH/PEX is a high-capacity cylindrical roller bearing with 240 mm bore, 440 mm OD and 120 mm width per ISO 15. SKF lists C 2279 kN, C0 3050 kN, Pu 275 kN, reference speed 1,600 r/min and limiting speed 1,700 r/min, mass about 80000 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2248-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2248-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2248-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 240×440×120 mm, but catalogue C/C0 ratings differ between executions (2279/3050 vs 1980/3050 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2248-ECMH-PEX",
      "SKF NUH 2248 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2320-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2320 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 710,
    "static_load_kN": 800,
    "fatigue_load_limit_kN": 91.5,
    "max_rpm": 3800,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3800,
    "weight_g": 13000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2320 ECMH is a high-capacity cylindrical roller bearing sized 100×215×73 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 100 mm seat is about 7.10 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 800 kN for static checks such as crane hook blocks standing under load. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "wind-turbine rotor pinion shafts",
      "heavy mining and cement gear drives",
      "wind turbine gearbox planetary and intermediate shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2320 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "The 710/800 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2320-ECMH?",
        "a": "SKF NUH 2320 ECMH is a high-capacity cylindrical roller bearing with 100 mm bore, 215 mm OD and 73 mm width per ISO 15. SKF lists C 710 kN, C0 800 kN, Pu 91.5 kN, reference speed 3,200 r/min and limiting speed 3,800 r/min, mass about 13000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2320-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2320-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2320",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2320-ECMH",
      "SKF NUH 2320 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2322-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2322 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 830,
    "static_load_kN": 965,
    "fatigue_load_limit_kN": 110,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 18000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2322-ECMH is the 110 mm bore entry in the NUH2300 range: a 110×240×80 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 830 kN / C0 965 kN. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.16 (965 against 830 kN), and the Pu figure 110 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "wind-turbine rotor pinion shafts",
      "heavy mining and cement gear drives",
      "wind turbine gearbox planetary and intermediate shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2322 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 830/965 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2322-ECMH?",
        "a": "SKF NUH 2322 ECMH is a high-capacity cylindrical roller bearing with 110 mm bore, 240 mm OD and 80 mm width per ISO 15. SKF lists C 830 kN, C0 965 kN, Pu 110 kN, reference speed 3,000 r/min and limiting speed 3,400 r/min, mass about 18000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2322-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2322-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2322",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2322-ECMH",
      "SKF NUH 2322 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2324-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2324 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 965,
    "static_load_kN": 1120,
    "fatigue_load_limit_kN": 125,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2324 ECMH is a high-capacity cylindrical roller bearing sized 120×260×86 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). With C 965 kN and C0 1120 kN, size the bearing on the 120×260 mm ISO 15 envelope and check the 125 kN Pu against the equivalent-load floor; the catalogue lists 2,800 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2324 using the /PEX loads.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 86 mm-wide ring and concentrates load.",
      "The 965/1120 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2324-ECMH?",
        "a": "SKF NUH 2324 ECMH is a high-capacity cylindrical roller bearing with 120 mm bore, 260 mm OD and 86 mm width per ISO 15. SKF lists C 965 kN, C0 1120 kN, Pu 125 kN, reference speed 2,800 r/min and limiting speed 3,200 r/min, mass about 22500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2324-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2324-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2324",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2324-ECMH",
      "SKF NUH 2324 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2326-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2326 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 93,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1120,
    "static_load_kN": 1340,
    "fatigue_load_limit_kN": 146,
    "max_rpm": 3000,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3000,
    "weight_g": 28000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2326 ECMH resolves to a 130×280×93 mm high-capacity cylindrical roller bearing (dimension series 23 (medium-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Load-per-bore for the 130 mm seat is about 8.62 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 1340 kN for static checks such as crane hook blocks standing under load. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2326 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 280 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 93 mm-wide ring and concentrates load.",
      "The 1120/1340 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2326-ECMH?",
        "a": "SKF NUH 2326 ECMH is a high-capacity cylindrical roller bearing with 130 mm bore, 280 mm OD and 93 mm width per ISO 15. SKF lists C 1120 kN, C0 1340 kN, Pu 146 kN, reference speed 2,400 r/min and limiting speed 3,000 r/min, mass about 28000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2326-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2326-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2326-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×93 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2326-ECMH",
      "SKF NUH 2326 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2328-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2328 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1250,
    "static_load_kN": 1530,
    "fatigue_load_limit_kN": 163,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 35000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2328 ECMH is a high-capacity cylindrical roller bearing sized 140×300×102 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Selection arithmetic: C0/C ≈ 1.22 (1530 against 1250 kN), and the Pu figure 163 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2328 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 102 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1250/1530 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2328-ECMH?",
        "a": "SKF NUH 2328 ECMH is a high-capacity cylindrical roller bearing with 140 mm bore, 300 mm OD and 102 mm width per ISO 15. SKF lists C 1250 kN, C0 1530 kN, Pu 163 kN, reference speed 2,400 r/min and limiting speed 2,800 r/min, mass about 35000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2328-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2328-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2328-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×102 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2328-ECMH",
      "SKF NUH 2328 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2330-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2330 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 320,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1430,
    "static_load_kN": 1760,
    "fatigue_load_limit_kN": 183,
    "max_rpm": 2600,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2600,
    "weight_g": 42000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 150 mm shaft, SKF lists NUH2330-ECMH as high-capacity cylindrical roller: 320 mm OD, 108 mm wide, Pu 183 kN, the catalogue lists 2,200 r/min thermal reference speed and 2,600 r/min mechanical limiting speed. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.23 (1760 against 1430 kN), and the Pu figure 183 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,200 r/min thermal reference speed and 2,600 r/min mechanical limiting speed. Fit practice for NUH2330-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2330 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 320 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1430/1760 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2330-ECMH?",
        "a": "SKF NUH 2330 ECMH is a high-capacity cylindrical roller bearing with 150 mm bore, 320 mm OD and 108 mm width per ISO 15. SKF lists C 1430 kN, C0 1760 kN, Pu 183 kN, reference speed 2,200 r/min and limiting speed 2,600 r/min, mass about 42000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2330-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2330-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2330-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×320×108 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2330-ECMH",
      "SKF NUH 2330 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2332-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2332 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 114,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1400,
    "static_load_kN": 2000,
    "fatigue_load_limit_kN": 196,
    "max_rpm": 2400,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 2400,
    "weight_g": 50500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUH 2332 ECMH denotes a high-capacity cylindrical roller bearing on the ISO 15 160×340×114 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 50500 g. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 1400 kN and C0 2000 kN, size the bearing on the 160×340 mm ISO 15 envelope and check the 196 kN Pu against the equivalent-load floor; the catalogue lists 1,800 r/min thermal reference speed and 2,400 r/min mechanical limiting speed. Fit practice for NUH2332-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2332 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 114 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1400/2000 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2332-ECMH?",
        "a": "SKF NUH 2332 ECMH is a high-capacity cylindrical roller bearing with 160 mm bore, 340 mm OD and 114 mm width per ISO 15. SKF lists C 1400 kN, C0 2000 kN, Pu 196 kN, reference speed 1,800 r/min and limiting speed 2,400 r/min, mass about 50500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2332-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2332-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2332-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×340×114 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NCF2332-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 160×340×114 mm, but catalogue C/C0 ratings differ between executions (1400/2000 vs 1600/2000 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2332-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 160×340×114 mm, but catalogue C/C0 ratings differ between executions (1400/2000 vs 1600/2000 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2332-ECMH",
      "SKF NUH 2332 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2332-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2332 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 114,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1600,
    "static_load_kN": 2000,
    "fatigue_load_limit_kN": 196,
    "max_rpm": 2400,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2400,
    "weight_g": 50500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2332 ECMH/PEX resolves to a 160×340×114 mm high-capacity cylindrical roller bearing (dimension series 23 (medium-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. With C 1600 kN and C0 2000 kN, size the bearing on the 160×340 mm ISO 15 envelope and check the 196 kN Pu against the equivalent-load floor; the catalogue lists 2,000 r/min thermal reference speed and 2,400 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 160 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 1600 kN / C0 2000 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2332-ECMH-PEX as a separate service part: do not substitute the standard NUH 2332 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2332 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 340 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 340 mm raceway.",
      "The 1600/2000 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2332-ECMH-PEX?",
        "a": "SKF NUH 2332 ECMH/PEX is a high-capacity cylindrical roller bearing with 160 mm bore, 340 mm OD and 114 mm width per ISO 15. SKF lists C 1600 kN, C0 2000 kN, Pu 196 kN, reference speed 2,000 r/min and limiting speed 2,400 r/min, mass about 50500 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2332-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2332-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2332-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 160×340×114 mm, but catalogue C/C0 ratings differ between executions (1600/2000 vs 1400/2000 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NCF2332-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×340×114 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2332-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 160×340×114 mm, but catalogue C/C0 ratings differ between executions (1600/2000 vs 1400/2000 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2332-ECMH-PEX",
      "SKF NUH 2332 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2334-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2334 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 360,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1540,
    "static_load_kN": 2200,
    "fatigue_load_limit_kN": 216,
    "max_rpm": 2200,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 2200,
    "weight_g": 59500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 170 mm shaft, SKF lists NUH2334-ECMH as high-capacity cylindrical roller: 360 mm OD, 120 mm wide, Pu 216 kN, the catalogue lists 1,700 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Load-per-bore for the 170 mm seat is about 9.06 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 2200 kN for static checks such as crane hook blocks standing under load. Assembly note: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Heat steel rings inductively to max 120 °C. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2334 using the /PEX loads.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1540/2200 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2334-ECMH?",
        "a": "SKF NUH 2334 ECMH is a high-capacity cylindrical roller bearing with 170 mm bore, 360 mm OD and 120 mm width per ISO 15. SKF lists C 1540 kN, C0 2200 kN, Pu 216 kN, reference speed 1,700 r/min and limiting speed 2,200 r/min, mass about 59500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2334-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2334-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2334-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 170×360×120 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NCF2334-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 170×360×120 mm, but catalogue C/C0 ratings differ between executions (1540/2200 vs 1760/2200 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2334-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 170×360×120 mm, but catalogue C/C0 ratings differ between executions (1540/2200 vs 1760/2200 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2334-ECMH",
      "SKF NUH 2334 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2334-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2334 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 170,
    "D_mm": 360,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1760,
    "static_load_kN": 2200,
    "fatigue_load_limit_kN": 216,
    "max_rpm": 2200,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2200,
    "weight_g": 59500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2334 ECMH/PEX is a high-capacity cylindrical roller bearing sized 170×360×120 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Speed planning for NUH2334-ECMH-PEX: the catalogue lists 1,900 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. The mass entry 59500 g covers the complete catalogue execution. Fit practice for NUH2334-ECMH-PEX: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 1760 kN / C0 2200 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2334-ECMH-PEX as a separate service part: do not substitute the standard NUH 2334 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2334 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 360 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 360 mm raceway.",
      "The 1760/2200 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2334-ECMH-PEX?",
        "a": "SKF NUH 2334 ECMH/PEX is a high-capacity cylindrical roller bearing with 170 mm bore, 360 mm OD and 120 mm width per ISO 15. SKF lists C 1760 kN, C0 2200 kN, Pu 216 kN, reference speed 1,900 r/min and limiting speed 2,200 r/min, mass about 59500 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2334-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2334-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2334-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 170×360×120 mm, but catalogue C/C0 ratings differ between executions (1760/2200 vs 1540/2200 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NCF2334-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 170×360×120 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2334-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 170×360×120 mm, but catalogue C/C0 ratings differ between executions (1760/2200 vs 1540/2200 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2334-ECMH-PEX",
      "SKF NUH 2334 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2336-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2336 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 380,
    "B_mm": 126,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1720,
    "static_load_kN": 2400,
    "fatigue_load_limit_kN": 232,
    "max_rpm": 2200,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 2200,
    "weight_g": 68000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUH 2336 ECMH denotes a high-capacity cylindrical roller bearing on the ISO 15 180×380×126 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 68000 g. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.40 (2400 against 1720 kN), and the Pu figure 232 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 2,200 r/min mechanical limiting speed. Fit practice for NUH2336-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2336 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "The 1720/2400 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2336-ECMH?",
        "a": "SKF NUH 2336 ECMH is a high-capacity cylindrical roller bearing with 180 mm bore, 380 mm OD and 126 mm width per ISO 15. SKF lists C 1720 kN, C0 2400 kN, Pu 232 kN, reference speed 1,600 r/min and limiting speed 2,200 r/min, mass about 68000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2336-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2336-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2336-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×380×126 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NCF2336-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 180×380×126 mm, but catalogue C/C0 ratings differ between executions (1720/2400 vs 1960/2400 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2336-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 180×380×126 mm, but catalogue C/C0 ratings differ between executions (1720/2400 vs 1960/2400 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2336-ECMH",
      "SKF NUH 2336 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2336-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2336 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 180,
    "D_mm": 380,
    "B_mm": 126,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1960,
    "static_load_kN": 2400,
    "fatigue_load_limit_kN": 232,
    "max_rpm": 2200,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 2200,
    "weight_g": 68000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2336 ECMH/PEX resolves to a 180×380×126 mm high-capacity cylindrical roller bearing (dimension series 23 (medium-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Load-per-bore for the 180 mm seat is about 10.89 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 2400 kN for static checks such as crane hook blocks standing under load. Fit practice for NUH2336-ECMH-PEX: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 1960 kN / C0 2400 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2336-ECMH-PEX as a separate service part: do not substitute the standard NUH 2336 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2336 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 380 mm raceway.",
      "The 1960/2400 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2336-ECMH-PEX?",
        "a": "SKF NUH 2336 ECMH/PEX is a high-capacity cylindrical roller bearing with 180 mm bore, 380 mm OD and 126 mm width per ISO 15. SKF lists C 1960 kN, C0 2400 kN, Pu 232 kN, reference speed 1,800 r/min and limiting speed 2,200 r/min, mass about 68000 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2336-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2336-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2336-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 180×380×126 mm, but catalogue C/C0 ratings differ between executions (1960/2400 vs 1720/2400 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NCF2336-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 180×380×126 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2336-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 180×380×126 mm, but catalogue C/C0 ratings differ between executions (1960/2400 vs 1720/2400 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2336-ECMH-PEX",
      "SKF NUH 2336 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2338-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2338 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 400,
    "B_mm": 132,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1940,
    "static_load_kN": 2750,
    "fatigue_load_limit_kN": 255,
    "max_rpm": 2000,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 2000,
    "weight_g": 78500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2338-ECMH is the 190 mm bore entry in the NUH2300 range: a 190×400×132 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 1940 kN / C0 2750 kN. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). With C 1940 kN and C0 2750 kN, size the bearing on the 190×400 mm ISO 15 envelope and check the 255 kN Pu against the equivalent-load floor; the catalogue lists 1,500 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Fit practice for NUH2338-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2338 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 132 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 1940/2750 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2338-ECMH?",
        "a": "SKF NUH 2338 ECMH is a high-capacity cylindrical roller bearing with 190 mm bore, 400 mm OD and 132 mm width per ISO 15. SKF lists C 1940 kN, C0 2750 kN, Pu 255 kN, reference speed 1,500 r/min and limiting speed 2,000 r/min, mass about 78500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2338-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2338-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2338-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×400×132 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NCF2338-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 190×400×132 mm, but catalogue C/C0 ratings differ between executions (1940/2750 vs 2240/2750 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2338-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 190×400×132 mm, but catalogue C/C0 ratings differ between executions (1940/2750 vs 2240/2750 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2338-ECMH",
      "SKF NUH 2338 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2338-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2338 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 400,
    "B_mm": 132,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2240,
    "static_load_kN": 2750,
    "fatigue_load_limit_kN": 255,
    "max_rpm": 2000,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 2000,
    "weight_g": 78500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 190 mm shaft, SKF lists NUH2338-ECMH-PEX as high-capacity cylindrical roller: 400 mm OD, 132 mm wide, Pu 255 kN, the catalogue lists 1,700 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.23 (2750 against 2240 kN), and the Pu figure 255 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,700 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. Fit practice for NUH2338-ECMH-PEX: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 2240 kN / C0 2750 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2338-ECMH-PEX as a separate service part: do not substitute the standard NUH 2338 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2338 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "The 2240/2750 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2338-ECMH-PEX?",
        "a": "SKF NUH 2338 ECMH/PEX is a high-capacity cylindrical roller bearing with 190 mm bore, 400 mm OD and 132 mm width per ISO 15. SKF lists C 2240 kN, C0 2750 kN, Pu 255 kN, reference speed 1,700 r/min and limiting speed 2,000 r/min, mass about 78500 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2338-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2338-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2338-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 190×400×132 mm, but catalogue C/C0 ratings differ between executions (2240/2750 vs 1940/2750 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NCF2338-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×400×132 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2338-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 190×400×132 mm, but catalogue C/C0 ratings differ between executions (2240/2750 vs 1940/2750 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2338-ECMH-PEX",
      "SKF NUH 2338 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2340-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2340 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 420,
    "B_mm": 138,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2200,
    "static_load_kN": 3200,
    "fatigue_load_limit_kN": 300,
    "max_rpm": 1900,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 1900,
    "weight_g": 92500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUH2340-ECMH is the 200 mm bore entry in the NUH2300 range: a 200×420×138 mm high-capacity cylindrical roller bearing with a one-piece machined brass cage, rated C 2200 kN / C0 3200 kN. The NUH configuration means a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring; functionally the bearing is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). With C 2200 kN and C0 3200 kN, size the bearing on the 200×420 mm ISO 15 envelope and check the 300 kN Pu against the equivalent-load floor; the catalogue lists 1,400 r/min thermal reference speed and 1,900 r/min mechanical limiting speed. Fit practice for NUH2340-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2340 using the /PEX loads.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 420 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 420 mm raceway.",
      "The 2200/3200 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2340-ECMH?",
        "a": "SKF NUH 2340 ECMH is a high-capacity cylindrical roller bearing with 200 mm bore, 420 mm OD and 138 mm width per ISO 15. SKF lists C 2200 kN, C0 3200 kN, Pu 300 kN, reference speed 1,400 r/min and limiting speed 1,900 r/min, mass about 92500 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2340-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2340-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2340-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×420×138 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NCF2340-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 200×420×138 mm, but catalogue C/C0 ratings differ between executions (2200/3200 vs 2550/3200 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2340-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 200×420×138 mm, but catalogue C/C0 ratings differ between executions (2200/3200 vs 2550/3200 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2340-ECMH",
      "SKF NUH 2340 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2340-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2340 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 200,
    "D_mm": 420,
    "B_mm": 138,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2550,
    "static_load_kN": 3200,
    "fatigue_load_limit_kN": 300,
    "max_rpm": 1900,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 1900,
    "weight_g": 92500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2340 ECMH/PEX is a high-capacity cylindrical roller bearing sized 200×420×138 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Selection arithmetic: C0/C ≈ 1.25 (3200 against 2550 kN), and the Pu figure 300 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,600 r/min thermal reference speed and 1,900 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 200 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 2550 kN / C0 3200 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2340-ECMH-PEX as a separate service part: do not substitute the standard NUH 2340 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2340 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 2550/3200 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2340-ECMH-PEX?",
        "a": "SKF NUH 2340 ECMH/PEX is a high-capacity cylindrical roller bearing with 200 mm bore, 420 mm OD and 138 mm width per ISO 15. SKF lists C 2550 kN, C0 3200 kN, Pu 300 kN, reference speed 1,600 r/min and limiting speed 1,900 r/min, mass about 92500 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2340-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2340-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2340-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 200×420×138 mm, but catalogue C/C0 ratings differ between executions (2550/3200 vs 2200/3200 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NCF2340-ECJB-PEX",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 200×420×138 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2340-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 200×420×138 mm, but catalogue C/C0 ratings differ between executions (2550/3200 vs 2200/3200 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2340-ECMH-PEX",
      "SKF NUH 2340 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2344-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2344 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 460,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2510,
    "static_load_kN": 3650,
    "fatigue_load_limit_kN": 335,
    "max_rpm": 1700,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 1700,
    "weight_g": 116000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2344 ECMH resolves to a 220×460×145 mm high-capacity cylindrical roller bearing (dimension series 23 (medium-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.45 (3650 against 2510 kN), and the Pu figure 335 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 1,300 r/min thermal reference speed and 1,700 r/min mechanical limiting speed. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 220 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2344 using the /PEX loads.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 145 mm-wide ring and concentrates load.",
      "The 2510/3650 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2344-ECMH?",
        "a": "SKF NUH 2344 ECMH is a high-capacity cylindrical roller bearing with 220 mm bore, 460 mm OD and 145 mm width per ISO 15. SKF lists C 2510 kN, C0 3650 kN, Pu 335 kN, reference speed 1,300 r/min and limiting speed 1,700 r/min, mass about 116000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2344-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2344-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2344-ECJB",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×460×145 mm and equivalent catalogue ratings; the NCF execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NUH2344-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×460×145 mm, but catalogue C/C0 ratings differ between executions (2510/3650 vs 2900/3650 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2344-ECMH",
      "SKF NUH 2344 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2344-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2344 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 460,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2900,
    "static_load_kN": 3650,
    "fatigue_load_limit_kN": 335,
    "max_rpm": 1700,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 1700,
    "weight_g": 116000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2344 ECMH/PEX is a high-capacity cylindrical roller bearing sized 220×460×145 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. The radial section height is 120.0 mm and the catalogue mass 116000 g; at 2900 kN dynamic rating this is roughly 13.18 kN of C per millimetre of bore before application factors. Mounting: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. A 220 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 2900 kN / C0 3650 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2344-ECMH-PEX as a separate service part: do not substitute the standard NUH 2344 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2344 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 460 mm raceway.",
      "The 2900/3650 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2344-ECMH-PEX?",
        "a": "SKF NUH 2344 ECMH/PEX is a high-capacity cylindrical roller bearing with 220 mm bore, 460 mm OD and 145 mm width per ISO 15. SKF lists C 2900 kN, C0 3650 kN, Pu 335 kN, reference speed 1,400 r/min and limiting speed 1,700 r/min, mass about 116000 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2344-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2344-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NCF2344-ECJB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×460×145 mm, but catalogue C/C0 ratings differ between executions (2900/3650 vs 2510/3650 kN) and the NCF flange/ring configuration differs — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NUH2344-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 220×460×145 mm, but catalogue C/C0 ratings differ between executions (2900/3650 vs 2510/3650 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2344-ECMH-PEX",
      "SKF NUH 2344 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2348-ECMH",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2348 ECMH",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 500,
    "B_mm": 155,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2750,
    "static_load_kN": 4000,
    "fatigue_load_limit_kN": 345,
    "max_rpm": 1500,
    "reference_speed_rpm": 1200,
    "limiting_speed_rpm": 1500,
    "weight_g": 143000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUH 2348 ECMH resolves to a 240×500×155 mm high-capacity cylindrical roller bearing (dimension series 23 (medium-section, wide)); a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. Reading the NUH prefix: a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. This makes the execution the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Load-per-bore for the 240 mm seat is about 11.46 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 4000 kN for static checks such as crane hook blocks standing under load. Fit practice for NUH2348-ECMH: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. This is the standard catalogue execution of the high-capacity design. Selected sizes in the range are also produced as /PEX pinion-shaft builds for wind-turbine gearboxes — separate order numbers with their own rating lines and internal profiling; the two must not be mixed using one another’s loads.",
    "applications": [
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts",
      "multi-megawatt wind turbine main gearboxes"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion execution carries its own rating line and internal geometry — never substitute a standard NUH 2348 using the /PEX loads.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 155 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 155 mm-wide ring and concentrates load.",
      "The 2750/4000 kN ratings are SKF catalogue 17000 (2018) values for the ECMH execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2348-ECMH?",
        "a": "SKF NUH 2348 ECMH is a high-capacity cylindrical roller bearing with 240 mm bore, 500 mm OD and 155 mm width per ISO 15. SKF lists C 2750 kN, C0 4000 kN, Pu 345 kN, reference speed 1,200 r/min and limiting speed 1,500 r/min, mass about 143000 g."
      },
      {
        "q": "What does the NUH designation and ECMH suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2348-ECMH take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2348-ECMH compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2348-ECMH-PEX",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 240×500×155 mm, but catalogue C/C0 ratings differ between executions (2750/4000 vs 3150/4000 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2348-ECMH",
      "SKF NUH 2348 ECMH"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUH2348-ECMH-PEX",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUH 2348 ECMH/PEX",
    "series": "NUH2300-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 500,
    "B_mm": 155,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 3150,
    "static_load_kN": 4000,
    "fatigue_load_limit_kN": 345,
    "max_rpm": 1500,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 1500,
    "weight_g": 143000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUH 2348 ECMH/PEX is a high-capacity cylindrical roller bearing sized 240×500×155 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.2. Structurally, the NUH design has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring. In arrangement terms it is the locating partner in paired cross-locating arrangements for heavily loaded shafts, locating axially in one direction. Reading the order-string suffix ECMH/PEX: the high-capacity execution with a machined brass cage (the /PEX variant is the pinion-shaft special build). Speed planning for NUH2348-ECMH-PEX: the catalogue lists 1,300 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. The mass entry 143000 g covers the complete catalogue execution. Fit practice for NUH2348-ECMH-PEX: typically paired with the matching NCF ECJB non-locating bearing on the same shaft; observe the catalogue shoulder and fillet data for the large inner ring. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment. The /PEX mark identifies the pinion-shaft build: it is the execution developed for the pinion position in wind-turbine and heavy industrial gearboxes, and SKF publishes its own rating line (C 3150 kN / C0 4000 kN here) because the roller complement and internal profiling differ from the standard execution. Treat NUH2348-ECMH-PEX as a separate service part: do not substitute the standard NUH 2348 bearing against the /PEX loads, and refit pinion arrangements with the same /PEX order number to preserve the calculated L10 and peak-torque margin.",
    "applications": [
      "multi-megawatt wind turbine main gearboxes",
      "offshore and marine heavy drive trains",
      "large mining mill pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "micro-pitting on the profiled rollers under contaminated or starved-lubricant conditions despite the black-oxide treatment",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "cage fatigue in heavily reversing wind-turbine load cycles when relubrication intervals are exceeded",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "High-capacity NUH and NCF bearings are designed as a locating/non-locating PAIR on the same shaft; fitting two locating NUH bearings can preload the arrangement thermally.",
      "The /PEX pinion build and the standard NUH 2348 bearing are separate service parts with different internal profiling and rating lines; replacing the /PEX part with the standard execution silently erases the peak-torque margin the gearbox was designed for.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 500 mm raceway.",
      "The 3150/4000 kN ratings are SKF catalogue 17000 (2018) values for the ECMH/PEX execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUH2348-ECMH-PEX?",
        "a": "SKF NUH 2348 ECMH/PEX is a high-capacity cylindrical roller bearing with 240 mm bore, 500 mm OD and 155 mm width per ISO 15. SKF lists C 3150 kN, C0 4000 kN, Pu 345 kN, reference speed 1,300 r/min and limiting speed 1,500 r/min, mass about 143000 g."
      },
      {
        "q": "What does the NUH designation and ECMH/PEX suffix mean?",
        "a": "The ECMH suffix denotes the high-capacity execution with a machined brass cage; the /PEX variant is the pinion-shaft special build. Structurally this execution has a high-capacity NJ-type execution whose displaced cage bars make room for additional rollers, with two integral flanges on the inner ring."
      },
      {
        "q": "Can NUH2348-ECMH-PEX take axial load and locate the shaft?",
        "a": "In one direction, as the locating member of a high-capacity pair; the matching NCF ECJB bearing floats. It is not a general-purpose axial bearing."
      },
      {
        "q": "How does NUH2348-ECMH-PEX compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUH2348-ECMH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same ISO 15 envelope 240×500×155 mm, but catalogue C/C0 ratings differ between executions (3150/4000 vs 2750/4000 kN) and the NUH flange/ring configuration differs — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.2 high-capacity cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUH2348-ECMH-PEX",
      "SKF NUH 2348 ECMH/PEX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP1017-ML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 1017 ML",
    "series": "NUP1000-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 130,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 68.2,
    "static_load_kN": 86.5,
    "fatigue_load_limit_kN": 10.8,
    "max_rpm": 9000,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 9000,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 85 mm shaft, SKF lists NUP1017-ML as single-row caged cylindrical roller: 130 mm OD, 22 mm wide, Pu 10.8 kN, the catalogue lists 6,000 r/min thermal reference speed and 9,000 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ML suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Speed planning for NUP1017-ML: the catalogue lists 6,000 r/min thermal reference speed and 9,000 r/min mechanical limiting speed. The mass entry 1100 g covers the complete catalogue execution. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 85 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 10 (extra-slim OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 1017, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 1017 ML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 22 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 130 mm raceway.",
      "The 68.2/86.5 kN ratings are SKF catalogue 17000 (2018) values for the ML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP1017-ML?",
        "a": "SKF NUP 1017 ML is a single-row caged cylindrical roller bearing with 85 mm bore, 130 mm OD and 22 mm width per ISO 15. SKF lists C 68.2 kN, C0 86.5 kN, Pu 10.8 kN, reference speed 6,000 r/min and limiting speed 9,000 r/min, mass about 1100 g."
      },
      {
        "q": "What does the NUP designation and ML suffix mean?",
        "a": "The ML suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP1017-ML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP1017-ML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP1017",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×130×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ1017-ML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×130×22 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU1017-ML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×130×22 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP1017-ML",
      "SKF NUP 1017 ML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP1880-MP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 1880 MP",
    "series": "NUP1800-series",
    "type": "cylindrical_roller",
    "d_mm": 400,
    "D_mm": 500,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 572,
    "static_load_kN": 1180,
    "fatigue_load_limit_kN": 96.5,
    "max_rpm": 1900,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 1900,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP1880-MP is the 400 mm bore entry in the NUP1800 range: a 400×500×46 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 572 kN / C0 1180 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The MP suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. The one-piece machined brass cage is reflected in the published speeds and temperature limits. The radial section height is 50.0 mm and the catalogue mass 22500 g; at 572 kN dynamic rating this is roughly 1.43 kN of C per millimetre of bore before application factors. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 400 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 18 (ultra-slim section for large shafts) envelope is shared with the N/NU/NJ/NUP executions of 1880, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 1880 MP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 46 mm-wide ring and concentrates load.",
      "The 572/1180 kN ratings are SKF catalogue 17000 (2018) values for the MP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP1880-MP?",
        "a": "SKF NUP 1880 MP is a single-row caged cylindrical roller bearing with 400 mm bore, 500 mm OD and 46 mm width per ISO 15. SKF lists C 572 kN, C0 1180 kN, Pu 96.5 kN, reference speed 1,300 r/min and limiting speed 1,900 r/min, mass about 22500 g."
      },
      {
        "q": "What does the NUP designation and MP suffix mean?",
        "a": "The MP suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP1880-MP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP1880-MP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ1880-MP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 400×500×46 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU1880-MP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 400×500×46 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP1880-MP",
      "SKF NUP 1880 MP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP203-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 203 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 20,
    "static_load_kN": 14.3,
    "fatigue_load_limit_kN": 1.73,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 72,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 203 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 17×40×12 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 72 g. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 11.5 mm and the catalogue mass 72 g; at 20 kN dynamic rating this is roughly 1.18 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts",
      "small pump rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 203, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 203 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 40 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 40 mm raceway.",
      "The 20/14.3 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP203-ECP?",
        "a": "SKF NUP 203 ECP is a single-row caged cylindrical roller bearing with 17 mm bore, 40 mm OD and 12 mm width per ISO 15. SKF lists C 20 kN, C0 14.3 kN, Pu 1.73 kN, reference speed 20,000 r/min and limiting speed 22,000 r/min, mass about 72 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP203-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP203-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×12 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×12 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×12 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP203-ECP",
      "SKF NUP 203 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP204-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 204 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 28.5,
    "static_load_kN": 22,
    "fatigue_load_limit_kN": 2.75,
    "max_rpm": 19000,
    "reference_speed_rpm": 17000,
    "limiting_speed_rpm": 19000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 204 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 20×47×14 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 120 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 28.5 kN and C0 22 kN, size the bearing on the 20×47 mm ISO 15 envelope and check the 2.75 kN Pu against the equivalent-load floor; the catalogue lists 17,000 r/min thermal reference speed and 19,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 20 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts",
      "small pump rotor shafts",
      "small industrial electric-motor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 204, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 204 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 14 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 47 mm raceway.",
      "The 28.5/22 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP204-ECP?",
        "a": "SKF NUP 204 ECP is a single-row caged cylindrical roller bearing with 20 mm bore, 47 mm OD and 14 mm width per ISO 15. SKF lists C 28.5 kN, C0 22 kN, Pu 2.75 kN, reference speed 17,000 r/min and limiting speed 19,000 r/min, mass about 120 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP204-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP204-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N204-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×47×14 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ204-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×47×14 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU204",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×47×14 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP204-ECP",
      "SKF NUP 204 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP205-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 205 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 27,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 16000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 16000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 205 ECP resolves to a 25×52×15 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Speed planning for NUP205-ECP: the catalogue lists 15,000 r/min thermal reference speed and 16,000 r/min mechanical limiting speed. The mass entry 140 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "appliance and fan armature shafts",
      "small pump rotor shafts",
      "small industrial electric-motor shafts",
      "light gearbox layshafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 205, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 205 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 52 mm raceway.",
      "The 32.5/27 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP205-ECP?",
        "a": "SKF NUP 205 ECP is a single-row caged cylindrical roller bearing with 25 mm bore, 52 mm OD and 15 mm width per ISO 15. SKF lists C 32.5 kN, C0 27 kN, Pu 3.35 kN, reference speed 15,000 r/min and limiting speed 16,000 r/min, mass about 140 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP205-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP205-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N205-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×52×15 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ205-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×52×15 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU205",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×52×15 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP205-ECP",
      "SKF NUP 205 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP206-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 206 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 44,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 4.55,
    "max_rpm": 14000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 14000,
    "weight_g": 210,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 206 ECP resolves to a 30×62×16 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 0.83 (36.5 against 44 kN), and the Pu figure 4.55 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 13,000 r/min thermal reference speed and 14,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 30 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 206, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 206 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 16 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 62 mm raceway.",
      "The 44/36.5 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP206-ECP?",
        "a": "SKF NUP 206 ECP is a single-row caged cylindrical roller bearing with 30 mm bore, 62 mm OD and 16 mm width per ISO 15. SKF lists C 44 kN, C0 36.5 kN, Pu 4.55 kN, reference speed 13,000 r/min and limiting speed 14,000 r/min, mass about 210 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP206-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP206-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N206-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×62×16 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ206-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×62×16 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU206",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×62×16 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP206-ECP",
      "SKF NUP 206 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP207-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 207 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 56,
    "static_load_kN": 48,
    "fatigue_load_limit_kN": 6.1,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP207-ECP is the 35 mm bore entry in the NUP200 range: a 35×72×17 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 56 kN / C0 48 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 18.5 mm and the catalogue mass 310 g; at 56 kN dynamic rating this is roughly 1.60 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 207, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 207 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 72 mm raceway.",
      "The 56/48 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP207-ECP?",
        "a": "SKF NUP 207 ECP is a single-row caged cylindrical roller bearing with 35 mm bore, 72 mm OD and 17 mm width per ISO 15. SKF lists C 56 kN, C0 48 kN, Pu 6.1 kN, reference speed 11,000 r/min and limiting speed 12,000 r/min, mass about 310 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP207-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP207-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N207-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×72×17 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ207-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×72×17 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU207",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×72×17 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP207-ECP",
      "SKF NUP 207 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP208-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 208 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 62,
    "static_load_kN": 53,
    "fatigue_load_limit_kN": 6.7,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 40 mm shaft, SKF lists NUP208-ECP as single-row caged cylindrical roller: 80 mm OD, 18 mm wide, Pu 6.7 kN, the catalogue lists 9,500 r/min thermal reference speed and 11,000 r/min mechanical limiting speed. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 62 kN and C0 53 kN, size the bearing on the 40×80 mm ISO 15 envelope and check the 6.7 kN Pu against the equivalent-load floor; the catalogue lists 9,500 r/min thermal reference speed and 11,000 r/min mechanical limiting speed. Fit practice for NUP208-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 208, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 208 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 80 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 80 mm raceway.",
      "The 62/53 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP208-ECP?",
        "a": "SKF NUP 208 ECP is a single-row caged cylindrical roller bearing with 40 mm bore, 80 mm OD and 18 mm width per ISO 15. SKF lists C 62 kN, C0 53 kN, Pu 6.7 kN, reference speed 9,500 r/min and limiting speed 11,000 r/min, mass about 390 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP208-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP208-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP208",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N208-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×80×18 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ208-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×80×18 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU208",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×80×18 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP208-ECP",
      "SKF NUP 208 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP209-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 209 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 69.5,
    "static_load_kN": 64,
    "fatigue_load_limit_kN": 8.15,
    "max_rpm": 9500,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 9500,
    "weight_g": 440,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 45 mm shaft, SKF lists NUP209-ECP as single-row caged cylindrical roller: 85 mm OD, 19 mm wide, Pu 8.15 kN, the catalogue lists 9,000 r/min thermal reference speed and 9,500 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Speed planning for NUP209-ECP: the catalogue lists 9,000 r/min thermal reference speed and 9,500 r/min mechanical limiting speed. The mass entry 440 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 209, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 209 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 19 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 85 mm raceway.",
      "The 69.5/64 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP209-ECP?",
        "a": "SKF NUP 209 ECP is a single-row caged cylindrical roller bearing with 45 mm bore, 85 mm OD and 19 mm width per ISO 15. SKF lists C 69.5 kN, C0 64 kN, Pu 8.15 kN, reference speed 9,000 r/min and limiting speed 9,500 r/min, mass about 440 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP209-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP209-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP209",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N209-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×85×19 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ209-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×85×19 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU209",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×85×19 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP209-ECP",
      "SKF NUP 209 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP210-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 210 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 73.5,
    "static_load_kN": 69.5,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 9000,
    "weight_g": 500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP210-ECP is the 50 mm bore entry in the NUP200 range: a 50×90×20 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 73.5 kN / C0 69.5 kN. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP210-ECP: the catalogue lists 8,500 r/min thermal reference speed and 9,000 r/min mechanical limiting speed. The mass entry 500 g covers the complete catalogue execution. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 50 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 210, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 210 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 90 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 73.5/69.5 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP210-ECP?",
        "a": "SKF NUP 210 ECP is a single-row caged cylindrical roller bearing with 50 mm bore, 90 mm OD and 20 mm width per ISO 15. SKF lists C 73.5 kN, C0 69.5 kN, Pu 8.8 kN, reference speed 8,500 r/min and limiting speed 9,000 r/min, mass about 500 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP210-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP210-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP210",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N210-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×90×20 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ210-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×90×20 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU210",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×90×20 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP210-ECP",
      "SKF NUP 210 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP211-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 211 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 96.5,
    "static_load_kN": 95,
    "fatigue_load_limit_kN": 12.2,
    "max_rpm": 8000,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8000,
    "weight_g": 680,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP211-ECP is the 55 mm bore entry in the NUP200 range: a 55×100×21 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 96.5 kN / C0 95 kN. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Load-per-bore for the 55 mm seat is about 1.75 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 95 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP211-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 211, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 211 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 21 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 96.5/95 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP211-ECP?",
        "a": "SKF NUP 211 ECP is a single-row caged cylindrical roller bearing with 55 mm bore, 100 mm OD and 21 mm width per ISO 15. SKF lists C 96.5 kN, C0 95 kN, Pu 12.2 kN, reference speed 7,500 r/min and limiting speed 8,000 r/min, mass about 680 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP211-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP211-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP211",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N211-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×100×21 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ211-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×100×21 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU211",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×100×21 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP211-ECP",
      "SKF NUP 211 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP212-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 212 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 108,
    "static_load_kN": 102,
    "fatigue_load_limit_kN": 13.4,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 860,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 60 mm shaft, SKF lists NUP212-ECP as single-row caged cylindrical roller: 110 mm OD, 22 mm wide, Pu 13.4 kN, the catalogue lists 6,700 r/min thermal reference speed and 7,500 r/min mechanical limiting speed. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 25.0 mm and the catalogue mass 860 g; at 108 kN dynamic rating this is roughly 1.80 kN of C per millimetre of bore before application factors. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 60 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 212, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 212 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 110 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 108/102 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP212-ECP?",
        "a": "SKF NUP 212 ECP is a single-row caged cylindrical roller bearing with 60 mm bore, 110 mm OD and 22 mm width per ISO 15. SKF lists C 108 kN, C0 102 kN, Pu 13.4 kN, reference speed 6,700 r/min and limiting speed 7,500 r/min, mass about 860 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP212-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP212-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP212",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N212-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×110×22 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ212-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×110×22 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU212",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×110×22 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP212-ECP",
      "SKF NUP 212 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP213-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 213 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 122,
    "static_load_kN": 118,
    "fatigue_load_limit_kN": 15.6,
    "max_rpm": 6700,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 6700,
    "weight_g": 1050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 65 mm shaft, SKF lists NUP213-ECP as single-row caged cylindrical roller: 120 mm OD, 23 mm wide, Pu 15.6 kN, the catalogue lists 6,300 r/min thermal reference speed and 6,700 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 122 kN and C0 118 kN, size the bearing on the 65×120 mm ISO 15 envelope and check the 15.6 kN Pu against the equivalent-load floor; the catalogue lists 6,300 r/min thermal reference speed and 6,700 r/min mechanical limiting speed. Fit practice for NUP213-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 213, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 213 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 23 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 122/118 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP213-ECP?",
        "a": "SKF NUP 213 ECP is a single-row caged cylindrical roller bearing with 65 mm bore, 120 mm OD and 23 mm width per ISO 15. SKF lists C 122 kN, C0 118 kN, Pu 15.6 kN, reference speed 6,300 r/min and limiting speed 6,700 r/min, mass about 1050 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP213-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP213-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP213",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N213-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×23 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ213-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU213",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×23 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP213-ECP",
      "SKF NUP 213 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP214-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 214 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 137,
    "static_load_kN": 137,
    "fatigue_load_limit_kN": 18,
    "max_rpm": 6300,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6300,
    "weight_g": 1200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 214 ECP is a single-row caged cylindrical roller bearing sized 70×125×24 mm — a dimension series 2 (light-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP214-ECP: the catalogue lists 6,000 r/min thermal reference speed and 6,300 r/min mechanical limiting speed. The mass entry 1200 g covers the complete catalogue execution. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 70 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 214, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 214 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 137/137 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP214-ECP?",
        "a": "SKF NUP 214 ECP is a single-row caged cylindrical roller bearing with 70 mm bore, 125 mm OD and 24 mm width per ISO 15. SKF lists C 137 kN, C0 137 kN, Pu 18 kN, reference speed 6,000 r/min and limiting speed 6,300 r/min, mass about 1200 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP214-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP214-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP214",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N214-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×24 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ214-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×24 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU214",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×24 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP214-ECP",
      "SKF NUP 214 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP215-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 215 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 150,
    "static_load_kN": 156,
    "fatigue_load_limit_kN": 20.4,
    "max_rpm": 6000,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6000,
    "weight_g": 1300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 215 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 75×130×25 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 1300 g. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 75 mm seat is about 2.00 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 156 kN for static checks such as crane hook blocks standing under load. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 215, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 215 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 130 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 150/156 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP215-ECP?",
        "a": "SKF NUP 215 ECP is a single-row caged cylindrical roller bearing with 75 mm bore, 130 mm OD and 25 mm width per ISO 15. SKF lists C 150 kN, C0 156 kN, Pu 20.4 kN, reference speed 5,600 r/min and limiting speed 6,000 r/min, mass about 1300 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP215-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP215-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP215",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N215-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×25 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ215-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×25 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU215",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×25 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP215-ECP",
      "SKF NUP 215 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP216-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 216 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 160,
    "static_load_kN": 166,
    "fatigue_load_limit_kN": 21.2,
    "max_rpm": 5600,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 5600,
    "weight_g": 1550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 216 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 80×140×26 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 1550 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.04 (166 against 160 kN), and the Pu figure 21.2 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 5,300 r/min thermal reference speed and 5,600 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 80 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 216, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 216 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 26 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 160/166 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP216-ECP?",
        "a": "SKF NUP 216 ECP is a single-row caged cylindrical roller bearing with 80 mm bore, 140 mm OD and 26 mm width per ISO 15. SKF lists C 160 kN, C0 166 kN, Pu 21.2 kN, reference speed 5,300 r/min and limiting speed 5,600 r/min, mass about 1550 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP216-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP216-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP216",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N216-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×26 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ216-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×26 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU216",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×26 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP216-ECP",
      "SKF NUP 216 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP217-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 217 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 190,
    "static_load_kN": 200,
    "fatigue_load_limit_kN": 25,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 1900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 217 ECP resolves to a 85×150×28 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 32.5 mm and the catalogue mass 1900 g; at 190 kN dynamic rating this is roughly 2.24 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 217, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 217 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 190/200 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP217-ECP?",
        "a": "SKF NUP 217 ECP is a single-row caged cylindrical roller bearing with 85 mm bore, 150 mm OD and 28 mm width per ISO 15. SKF lists C 190 kN, C0 200 kN, Pu 25 kN, reference speed 4,800 r/min and limiting speed 5,300 r/min, mass about 1900 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP217-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP217-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP217",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×150×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N217-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×28 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ217-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×28 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU217",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×28 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP217-ECP",
      "SKF NUP 217 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP218-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 218 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 208,
    "static_load_kN": 220,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 2450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 218 ECP resolves to a 90×160×30 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 208 kN and C0 220 kN, size the bearing on the 90×160 mm ISO 15 envelope and check the 27 kN Pu against the equivalent-load floor; the catalogue lists 4,500 r/min thermal reference speed and 5,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 90 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 218, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 218 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 160 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 208/220 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP218-ECP?",
        "a": "SKF NUP 218 ECP is a single-row caged cylindrical roller bearing with 90 mm bore, 160 mm OD and 30 mm width per ISO 15. SKF lists C 208 kN, C0 220 kN, Pu 27 kN, reference speed 4,500 r/min and limiting speed 5,000 r/min, mass about 2450 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP218-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP218-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP218",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N218-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×30 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ218-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×30 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU218",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×30 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP218-ECP",
      "SKF NUP 218 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP219-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 219 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 255,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 32.5,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 2900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP219-ECP is the 95 mm bore entry in the NUP200 range: a 95×170×32 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 255 kN / C0 265 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 95 mm seat is about 2.68 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 265 kN for static checks such as crane hook blocks standing under load. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 219, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 219 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 255/265 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP219-ECP?",
        "a": "SKF NUP 219 ECP is a single-row caged cylindrical roller bearing with 95 mm bore, 170 mm OD and 32 mm width per ISO 15. SKF lists C 255 kN, C0 265 kN, Pu 32.5 kN, reference speed 4,300 r/min and limiting speed 4,800 r/min, mass about 2900 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP219-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP219-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP219",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N219-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×32 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ219-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×32 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU219",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×32 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP219-ECP",
      "SKF NUP 219 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP220-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 220 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 285,
    "static_load_kN": 305,
    "fatigue_load_limit_kN": 36.5,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 3600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 220 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 100×180×34 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 3600 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.07 (305 against 285 kN), and the Pu figure 36.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 4,000 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 100 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 220, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 220 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 34 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "The 285/305 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP220-ECP?",
        "a": "SKF NUP 220 ECP is a single-row caged cylindrical roller bearing with 100 mm bore, 180 mm OD and 34 mm width per ISO 15. SKF lists C 285 kN, C0 305 kN, Pu 36.5 kN, reference speed 4,000 r/min and limiting speed 4,500 r/min, mass about 3600 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP220-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP220-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP220",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 100×180×34 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N220-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×34 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ220-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×34 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU220",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×34 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP220-ECP",
      "SKF NUP 220 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2203-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2203 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 21.6,
    "fatigue_load_limit_kN": 2.65,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 97,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 17 mm shaft, SKF lists NUP2203-ECP as single-row caged cylindrical roller: 40 mm OD, 16 mm wide, Pu 2.65 kN, the catalogue lists 20,000 r/min thermal reference speed and 22,000 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 0.79 (21.6 against 27.5 kN), and the Pu figure 2.65 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 20,000 r/min thermal reference speed and 22,000 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2203, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2203 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 16 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 27.5/21.6 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2203-ECP?",
        "a": "SKF NUP 2203 ECP is a single-row caged cylindrical roller bearing with 17 mm bore, 40 mm OD and 16 mm width per ISO 15. SKF lists C 27.5 kN, C0 21.6 kN, Pu 2.65 kN, reference speed 20,000 r/min and limiting speed 22,000 r/min, mass about 97 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2203-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2203-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×16 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2203-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 17×40×16 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2203-ECP",
      "SKF NUP 2203 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2205-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2205 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 39,
    "static_load_kN": 34,
    "fatigue_load_limit_kN": 4.25,
    "max_rpm": 16000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 16000,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2205 ECP is a single-row caged cylindrical roller bearing sized 25×52×18 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP2205-ECP: the catalogue lists 15,000 r/min thermal reference speed and 16,000 r/min mechanical limiting speed. The mass entry 170 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "appliance and fan armature shafts",
      "small pump rotor shafts",
      "small industrial electric-motor shafts",
      "light gearbox layshafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2205, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2205 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 18 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 39/34 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2205-ECP?",
        "a": "SKF NUP 2205 ECP is a single-row caged cylindrical roller bearing with 25 mm bore, 52 mm OD and 18 mm width per ISO 15. SKF lists C 39 kN, C0 34 kN, Pu 4.25 kN, reference speed 15,000 r/min and limiting speed 16,000 r/min, mass about 170 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2205-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2205-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2205-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×52×18 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2205",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×52×18 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2205-ECP",
      "SKF NUP 2205 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2206-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2206 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 55,
    "static_load_kN": 49,
    "fatigue_load_limit_kN": 6.1,
    "max_rpm": 14000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 14000,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2206 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 30×62×20 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 270 g. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Load-per-bore for the 30 mm seat is about 1.83 kN/mm, typical of dimension series 22 (light-section, wide); use C0 49 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP2206-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2206, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2206 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 55/49 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2206-ECP?",
        "a": "SKF NUP 2206 ECP is a single-row caged cylindrical roller bearing with 30 mm bore, 62 mm OD and 20 mm width per ISO 15. SKF lists C 55 kN, C0 49 kN, Pu 6.1 kN, reference speed 13,000 r/min and limiting speed 14,000 r/min, mass about 270 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2206-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2206-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2206-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×62×20 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2206",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×62×20 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2206-ECP",
      "SKF NUP 2206 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2207-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2207 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 69.5,
    "static_load_kN": 63,
    "fatigue_load_limit_kN": 8.15,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 420,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2207 ECP resolves to a 35×72×23 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 0.91 (63 against 69.5 kN), and the Pu figure 8.15 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 11,000 r/min thermal reference speed and 12,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 35 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2207, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2207 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 72 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 69.5/63 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2207-ECP?",
        "a": "SKF NUP 2207 ECP is a single-row caged cylindrical roller bearing with 35 mm bore, 72 mm OD and 23 mm width per ISO 15. SKF lists C 69.5 kN, C0 63 kN, Pu 8.15 kN, reference speed 11,000 r/min and limiting speed 12,000 r/min, mass about 420 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2207-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2207-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2207-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×72×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2207",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×72×23 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2207-ECP",
      "SKF NUP 2207 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2208-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2208 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 81.5,
    "static_load_kN": 75,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 510,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2208 ECP resolves to a 40×80×23 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 20.0 mm and the catalogue mass 510 g; at 81.5 kN dynamic rating this is roughly 2.04 kN of C per millimetre of bore before application factors. Fit practice for NUP2208-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2208, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2208 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 23 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 81.5/75 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2208-ECP?",
        "a": "SKF NUP 2208 ECP is a single-row caged cylindrical roller bearing with 40 mm bore, 80 mm OD and 23 mm width per ISO 15. SKF lists C 81.5 kN, C0 75 kN, Pu 9.65 kN, reference speed 9,500 r/min and limiting speed 11,000 r/min, mass about 510 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2208-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2208-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2208",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2208-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×80×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2208",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×80×23 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2208-ECP",
      "SKF NUP 2208 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2209-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2209 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 85,
    "static_load_kN": 81.5,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 9500,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 9500,
    "weight_g": 550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2209-ECP is the 45 mm bore entry in the NUP2200 range: a 45×85×23 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 85 kN / C0 81.5 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 20.0 mm and the catalogue mass 550 g; at 85 kN dynamic rating this is roughly 1.89 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2209, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2209 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 85 mm raceway.",
      "The 85/81.5 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2209-ECP?",
        "a": "SKF NUP 2209 ECP is a single-row caged cylindrical roller bearing with 45 mm bore, 85 mm OD and 23 mm width per ISO 15. SKF lists C 85 kN, C0 81.5 kN, Pu 10.6 kN, reference speed 9,000 r/min and limiting speed 9,500 r/min, mass about 550 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2209-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2209-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2209",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2209-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×85×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2209",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×85×23 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2209-ECP",
      "SKF NUP 2209 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP221-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 221 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 300,
    "static_load_kN": 315,
    "fatigue_load_limit_kN": 36.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 4200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 221 ECP resolves to a 105×190×36 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 42.5 mm and the catalogue mass 4200 g; at 300 kN dynamic rating this is roughly 2.86 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 221, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 221 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 190 mm raceway.",
      "The 300/315 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP221-ECP?",
        "a": "SKF NUP 221 ECP is a single-row caged cylindrical roller bearing with 105 mm bore, 190 mm OD and 36 mm width per ISO 15. SKF lists C 300 kN, C0 315 kN, Pu 36.5 kN, reference speed 3,800 r/min and limiting speed 4,300 r/min, mass about 4200 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP221-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP221-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP221",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 105×190×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N221-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×190×36 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ221-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×190×36 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU221-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 105×190×36 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP221-ECP",
      "SKF NUP 221 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2210-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2210 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 90,
    "static_load_kN": 88,
    "fatigue_load_limit_kN": 11.4,
    "max_rpm": 9000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 9000,
    "weight_g": 590,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2210 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 50×90×23 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 590 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 90 kN and C0 88 kN, size the bearing on the 50×90 mm ISO 15 envelope and check the 11.4 kN Pu against the equivalent-load floor; the catalogue lists 8,500 r/min thermal reference speed and 9,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 50 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2210, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2210 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 23 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 23 mm-wide ring and concentrates load.",
      "The 90/88 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2210-ECP?",
        "a": "SKF NUP 2210 ECP is a single-row caged cylindrical roller bearing with 50 mm bore, 90 mm OD and 23 mm width per ISO 15. SKF lists C 90 kN, C0 88 kN, Pu 11.4 kN, reference speed 8,500 r/min and limiting speed 9,000 r/min, mass about 590 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2210-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2210-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2210",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2210-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×90×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2210",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×90×23 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2210-ECP",
      "SKF NUP 2210 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2211-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2211 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 114,
    "static_load_kN": 118,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 8000,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8000,
    "weight_g": 820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2211 ECP resolves to a 55×100×25 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP2211-ECP: the catalogue lists 7,500 r/min thermal reference speed and 8,000 r/min mechanical limiting speed. The mass entry 820 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2211, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2211 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 25 mm-wide ring and concentrates load.",
      "The 114/118 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2211-ECP?",
        "a": "SKF NUP 2211 ECP is a single-row caged cylindrical roller bearing with 55 mm bore, 100 mm OD and 25 mm width per ISO 15. SKF lists C 114 kN, C0 118 kN, Pu 15.3 kN, reference speed 7,500 r/min and limiting speed 8,000 r/min, mass about 820 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2211-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2211-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2211",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2211-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×100×25 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2211",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×100×25 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2211-ECP",
      "SKF NUP 2211 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2212-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2212 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 146,
    "static_load_kN": 153,
    "fatigue_load_limit_kN": 20,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2212 ECP resolves to a 60×110×28 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 1.05 (153 against 146 kN), and the Pu figure 20 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 6,700 r/min thermal reference speed and 7,500 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 60 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2212, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2212 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 28 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 28 mm-wide ring and concentrates load.",
      "The 146/153 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2212-ECP?",
        "a": "SKF NUP 2212 ECP is a single-row caged cylindrical roller bearing with 60 mm bore, 110 mm OD and 28 mm width per ISO 15. SKF lists C 146 kN, C0 153 kN, Pu 20 kN, reference speed 6,700 r/min and limiting speed 7,500 r/min, mass about 1100 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2212-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2212-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2212",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2212-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×110×28 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2212",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×110×28 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2212-ECP",
      "SKF NUP 2212 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2213-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2213 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 170,
    "static_load_kN": 180,
    "fatigue_load_limit_kN": 24,
    "max_rpm": 6700,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 6700,
    "weight_g": 1450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2213-ECP is the 65 mm bore entry in the NUP2200 range: a 65×120×31 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 170 kN / C0 180 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 27.5 mm and the catalogue mass 1450 g; at 170 kN dynamic rating this is roughly 2.62 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2213, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2213 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "The 170/180 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2213-ECP?",
        "a": "SKF NUP 2213 ECP is a single-row caged cylindrical roller bearing with 65 mm bore, 120 mm OD and 31 mm width per ISO 15. SKF lists C 170 kN, C0 180 kN, Pu 24 kN, reference speed 6,300 r/min and limiting speed 6,700 r/min, mass about 1450 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2213-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2213-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2213",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2213-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2213-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×120×31 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2213-ECP",
      "SKF NUP 2213 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2214-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2214 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 180,
    "static_load_kN": 193,
    "fatigue_load_limit_kN": 25.5,
    "max_rpm": 6300,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6300,
    "weight_g": 1550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2214-ECP is the 70 mm bore entry in the NUP2200 range: a 70×125×31 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 180 kN / C0 193 kN. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 180 kN and C0 193 kN, size the bearing on the 70×125 mm ISO 15 envelope and check the 25.5 kN Pu against the equivalent-load floor; the catalogue lists 6,000 r/min thermal reference speed and 6,300 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 70 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2214, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2214 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 125 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "The 180/193 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2214-ECP?",
        "a": "SKF NUP 2214 ECP is a single-row caged cylindrical roller bearing with 70 mm bore, 125 mm OD and 31 mm width per ISO 15. SKF lists C 180 kN, C0 193 kN, Pu 25.5 kN, reference speed 6,000 r/min and limiting speed 6,300 r/min, mass about 1550 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2214-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2214-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2214",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2214-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2214-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×125×31 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2214-ECP",
      "SKF NUP 2214 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2215-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2215 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 186,
    "static_load_kN": 208,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 6000,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6000,
    "weight_g": 1600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 75 mm shaft, SKF lists NUP2215-ECP as single-row caged cylindrical roller: 130 mm OD, 31 mm wide, Pu 27 kN, the catalogue lists 5,600 r/min thermal reference speed and 6,000 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP2215-ECP: the catalogue lists 5,600 r/min thermal reference speed and 6,000 r/min mechanical limiting speed. The mass entry 1600 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2215, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2215 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "The 186/208 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2215-ECP?",
        "a": "SKF NUP 2215 ECP is a single-row caged cylindrical roller bearing with 75 mm bore, 130 mm OD and 31 mm width per ISO 15. SKF lists C 186 kN, C0 208 kN, Pu 27 kN, reference speed 5,600 r/min and limiting speed 6,000 r/min, mass about 1600 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2215-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2215-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2215",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2215-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2215-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×130×31 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2215-ECP",
      "SKF NUP 2215 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2216-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2216 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 212,
    "static_load_kN": 245,
    "fatigue_load_limit_kN": 31,
    "max_rpm": 5600,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 5600,
    "weight_g": 2000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2216 ECP is a single-row caged cylindrical roller bearing sized 80×140×33 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 80 mm seat is about 2.65 kN/mm, typical of dimension series 22 (light-section, wide); use C0 245 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP2216-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2216, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2216 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 33 mm-wide ring and concentrates load.",
      "The 212/245 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2216-ECP?",
        "a": "SKF NUP 2216 ECP is a single-row caged cylindrical roller bearing with 80 mm bore, 140 mm OD and 33 mm width per ISO 15. SKF lists C 212 kN, C0 245 kN, Pu 31 kN, reference speed 5,300 r/min and limiting speed 5,600 r/min, mass about 2000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2216-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2216-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2216",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2216-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×33 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2216-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×140×33 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2216-ECP",
      "SKF NUP 2216 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2217-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2217 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 250,
    "static_load_kN": 280,
    "fatigue_load_limit_kN": 34.5,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 2600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2217 ECP is a single-row caged cylindrical roller bearing sized 85×150×36 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.12 (280 against 250 kN), and the Pu figure 34.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 4,800 r/min thermal reference speed and 5,300 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2217, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2217 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 150 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 36 mm-wide ring and concentrates load.",
      "The 250/280 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2217-ECP?",
        "a": "SKF NUP 2217 ECP is a single-row caged cylindrical roller bearing with 85 mm bore, 150 mm OD and 36 mm width per ISO 15. SKF lists C 250 kN, C0 280 kN, Pu 34.5 kN, reference speed 4,800 r/min and limiting speed 5,300 r/min, mass about 2600 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2217-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2217-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2217",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×150×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2217-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×36 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2217-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×150×36 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2217-ECP",
      "SKF NUP 2217 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2218-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2218 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 280,
    "static_load_kN": 315,
    "fatigue_load_limit_kN": 39,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 3300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2218 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 90×160×40 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 3300 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 35.0 mm and the catalogue mass 3300 g; at 280 kN dynamic rating this is roughly 3.11 kN of C per millimetre of bore before application factors. Fit practice for NUP2218-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2218, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2218 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 40 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 40 mm-wide ring and concentrates load.",
      "The 280/315 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2218-ECP?",
        "a": "SKF NUP 2218 ECP is a single-row caged cylindrical roller bearing with 90 mm bore, 160 mm OD and 40 mm width per ISO 15. SKF lists C 280 kN, C0 315 kN, Pu 39 kN, reference speed 4,500 r/min and limiting speed 5,000 r/min, mass about 3300 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2218-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2218-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2218",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 90×160×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2218-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2218-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×160×40 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2218-ECP",
      "SKF NUP 2218 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2219-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2219 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 325,
    "static_load_kN": 375,
    "fatigue_load_limit_kN": 45.5,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 4000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2219 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 95×170×43 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 4000 g. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP2219-ECP: the catalogue lists 4,300 r/min thermal reference speed and 4,800 r/min mechanical limiting speed. The mass entry 4000 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2219, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2219 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 170 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 43 mm-wide ring and concentrates load.",
      "The 325/375 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2219-ECP?",
        "a": "SKF NUP 2219 ECP is a single-row caged cylindrical roller bearing with 95 mm bore, 170 mm OD and 43 mm width per ISO 15. SKF lists C 325 kN, C0 375 kN, Pu 45.5 kN, reference speed 4,300 r/min and limiting speed 4,800 r/min, mass about 4000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2219-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2219-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2219",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 95×170×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2219-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×43 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2219-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×170×43 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2219-ECP",
      "SKF NUP 2219 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP222-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 222 ECP",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 335,
    "static_load_kN": 365,
    "fatigue_load_limit_kN": 42.5,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 5000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 222 ECP resolves to a 110×200×38 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 335 kN and C0 365 kN, size the bearing on the 110×200 mm ISO 15 envelope and check the 42.5 kN Pu against the equivalent-load floor; the catalogue lists 3,600 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 110 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 222, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 222 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 335/365 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP222-ECP?",
        "a": "SKF NUP 222 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 200 mm OD and 38 mm width per ISO 15. SKF lists C 335 kN, C0 365 kN, Pu 42.5 kN, reference speed 3,600 r/min and limiting speed 4,000 r/min, mass about 5000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP222-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP222-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP222",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×38 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×38 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×38 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP222-ECP",
      "SKF NUP 222 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2220-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2220 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 380,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 54,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 4800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2220 ECP is a single-row caged cylindrical roller bearing sized 100×180×46 mm — a dimension series 22 (light-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Load-per-bore for the 100 mm seat is about 3.80 kN/mm, typical of dimension series 22 (light-section, wide); use C0 450 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP2220-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2220, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2220 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 380/450 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2220-ECP?",
        "a": "SKF NUP 2220 ECP is a single-row caged cylindrical roller bearing with 100 mm bore, 180 mm OD and 46 mm width per ISO 15. SKF lists C 380 kN, C0 450 kN, Pu 54 kN, reference speed 4,000 r/min and limiting speed 4,500 r/min, mass about 4800 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2220-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2220-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2220",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 100×180×46 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2220-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×46 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2220-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×180×46 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2220-ECP",
      "SKF NUP 2220 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2222-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2222 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 440,
    "static_load_kN": 520,
    "fatigue_load_limit_kN": 61,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 7000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2222 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 110×200×53 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 7000 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.18 (520 against 440 kN), and the Pu figure 61 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,600 r/min thermal reference speed and 4,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 110 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2222, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2222 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 53 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 440/520 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2222-ECP?",
        "a": "SKF NUP 2222 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 200 mm OD and 53 mm width per ISO 15. SKF lists C 440 kN, C0 520 kN, Pu 61 kN, reference speed 3,600 r/min and limiting speed 4,000 r/min, mass about 7000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2222-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2222-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2222",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×200×53 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×53 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2222-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×200×53 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2222-ECP",
      "SKF NUP 2222 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2224-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2224 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 520,
    "static_load_kN": 630,
    "fatigue_load_limit_kN": 72,
    "max_rpm": 3600,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3600,
    "weight_g": 8650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2224 ECP resolves to a 120×215×58 mm single-row caged cylindrical roller bearing (dimension series 22 (light-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 520 kN and C0 630 kN, size the bearing on the 120×215 mm ISO 15 envelope and check the 72 kN Pu against the equivalent-load floor; the catalogue lists 3,400 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 120 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2224, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2224 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "The 520/630 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2224-ECP?",
        "a": "SKF NUP 2224 ECP is a single-row caged cylindrical roller bearing with 120 mm bore, 215 mm OD and 58 mm width per ISO 15. SKF lists C 520 kN, C0 630 kN, Pu 72 kN, reference speed 3,400 r/min and limiting speed 3,600 r/min, mass about 8650 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2224-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2224-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2224",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×215×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2224-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×58 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2224-ECP",
      "SKF NUP 2224 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2226-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2226 ECP",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 610,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 83,
    "max_rpm": 3400,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3400,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2226-ECP is the 130 mm bore entry in the NUP2200 range: a 130×230×64 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 610 kN / C0 735 kN. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.20 (735 against 610 kN), and the Pu figure 83 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,200 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 130 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2226, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2226 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 230 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 230 mm raceway.",
      "The 610/735 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2226-ECP?",
        "a": "SKF NUP 2226 ECP is a single-row caged cylindrical roller bearing with 130 mm bore, 230 mm OD and 64 mm width per ISO 15. SKF lists C 610 kN, C0 735 kN, Pu 83 kN, reference speed 3,200 r/min and limiting speed 3,400 r/min, mass about 10500 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2226-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2226-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2226",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×230×64 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2226-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×64 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×64 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2226-ECP",
      "SKF NUP 2226 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2228-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2228 ECML",
    "series": "NUP2200-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 655,
    "static_load_kN": 830,
    "fatigue_load_limit_kN": 93,
    "max_rpm": 4800,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 4800,
    "weight_g": 15500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 140 mm shaft, SKF lists NUP2228-ECML as single-row caged cylindrical roller: 250 mm OD, 68 mm wide, Pu 93 kN, the catalogue lists 2,800 r/min thermal reference speed and 4,800 r/min mechanical limiting speed. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. Load-per-bore for the 140 mm seat is about 4.68 kN/mm, typical of dimension series 22 (light-section, wide); use C0 830 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP2228-ECML: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2228, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2228 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 655/830 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2228-ECML?",
        "a": "SKF NUP 2228 ECML is a single-row caged cylindrical roller bearing with 140 mm bore, 250 mm OD and 68 mm width per ISO 15. SKF lists C 655 kN, C0 830 kN, Pu 93 kN, reference speed 2,800 r/min and limiting speed 4,800 r/min, mass about 15500 g."
      },
      {
        "q": "What does the NUP designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2228-ECML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2228-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2228",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×250×68 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2228-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×68 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2228-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×68 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2228-ECML",
      "SKF NUP 2228 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP224-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 224 ECJ",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 390,
    "static_load_kN": 430,
    "fatigue_load_limit_kN": 49,
    "max_rpm": 3600,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3600,
    "weight_g": 5950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 224 ECJ denotes a single-row caged cylindrical roller bearing on the ISO 15 120×215×40 mm envelope, dimension series 2 (light-section ISO 15 envelope), with catalogue mass 5950 g. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECJ: the E-design execution with a pressed sheet-steel window cage, for positions where polymer cages are temperature- or lubricant-limited. Load-per-bore for the 120 mm seat is about 3.25 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 430 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP224-ECJ: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 224, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 224 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.",
      "The 390/430 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP224-ECJ?",
        "a": "SKF NUP 224 ECJ is a single-row caged cylindrical roller bearing with 120 mm bore, 215 mm OD and 40 mm width per ISO 15. SKF lists C 390 kN, C0 430 kN, Pu 49 kN, reference speed 3,400 r/min and limiting speed 3,600 r/min, mass about 5950 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP224-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP224-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP224",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×215×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×40 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU224-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×215×40 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP224-ECJ",
      "SKF NUP 224 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP226-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 226 ECJ",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 415,
    "static_load_kN": 455,
    "fatigue_load_limit_kN": 51,
    "max_rpm": 3400,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3400,
    "weight_g": 6500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 226 ECJ resolves to a 130×230×40 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. The pressed sheet-steel window-type cage is reflected in the published speeds and temperature limits. The radial section height is 50.0 mm and the catalogue mass 6500 g; at 415 kN dynamic rating this is roughly 3.19 kN of C per millimetre of bore before application factors. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 130 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 226, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 226 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 40 mm-wide ring and concentrates load.",
      "The 415/455 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP226-ECJ?",
        "a": "SKF NUP 226 ECJ is a single-row caged cylindrical roller bearing with 130 mm bore, 230 mm OD and 40 mm width per ISO 15. SKF lists C 415 kN, C0 455 kN, Pu 51 kN, reference speed 3,200 r/min and limiting speed 3,400 r/min, mass about 6500 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP226-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP226-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP226",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×230×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×40 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU226-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×230×40 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP226-ECJ",
      "SKF NUP 226 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP228-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 228 ECJ",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 450,
    "static_load_kN": 510,
    "fatigue_load_limit_kN": 57,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 8450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP228-ECJ is the 140 mm bore entry in the NUP200 range: a 140×250×42 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 450 kN / C0 510 kN. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. The pressed sheet-steel window-type cage is reflected in the published speeds and temperature limits. Speed planning for NUP228-ECJ: the catalogue lists 2,800 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. The mass entry 8450 g covers the complete catalogue execution. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 140 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 228, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 228 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 42 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 42 mm-wide ring and concentrates load.",
      "The 450/510 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP228-ECJ?",
        "a": "SKF NUP 228 ECJ is a single-row caged cylindrical roller bearing with 140 mm bore, 250 mm OD and 42 mm width per ISO 15. SKF lists C 450 kN, C0 510 kN, Pu 57 kN, reference speed 2,800 r/min and limiting speed 3,200 r/min, mass about 8450 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP228-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP228-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP228",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×250×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ228-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×42 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU228-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×250×42 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP228-ECJ",
      "SKF NUP 228 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP230-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 230 ECJ",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 510,
    "static_load_kN": 600,
    "fatigue_load_limit_kN": 64,
    "max_rpm": 2800,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 2800,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 230 ECJ resolves to a 150×270×45 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECJ: the E-design execution with a pressed sheet-steel window cage, for positions where polymer cages are temperature- or lubricant-limited. Selection arithmetic: C0/C ≈ 1.18 (600 against 510 kN), and the Pu figure 64 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,600 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 150 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 230, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 230 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 45 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 510/600 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP230-ECJ?",
        "a": "SKF NUP 230 ECJ is a single-row caged cylindrical roller bearing with 150 mm bore, 270 mm OD and 45 mm width per ISO 15. SKF lists C 510 kN, C0 600 kN, Pu 64 kN, reference speed 2,600 r/min and limiting speed 2,800 r/min, mass about 10500 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP230-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP230-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP230",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 150×270×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ230-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×270×45 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU230-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 150×270×45 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP230-ECJ",
      "SKF NUP 230 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2304-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2304 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 47.5,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 18000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 18000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2304-ECP is the 20 mm bore entry in the NUP2300 range: a 20×52×21 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 47.5 kN / C0 38 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 47.5 kN and C0 38 kN, size the bearing on the 20×52 mm ISO 15 envelope and check the 4.8 kN Pu against the equivalent-load floor; the catalogue lists 15,000 r/min thermal reference speed and 18,000 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts",
      "small pump rotor shafts",
      "small industrial electric-motor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2304, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2304 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 21 mm-wide ring and concentrates load.",
      "The 47.5/38 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2304-ECP?",
        "a": "SKF NUP 2304 ECP is a single-row caged cylindrical roller bearing with 20 mm bore, 52 mm OD and 21 mm width per ISO 15. SKF lists C 47.5 kN, C0 38 kN, Pu 4.8 kN, reference speed 15,000 r/min and limiting speed 18,000 r/min, mass about 220 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2304-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2304-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2304-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×21 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2304-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×21 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2304-ECP",
      "SKF NUP 2304 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2305-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2305 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 64,
    "static_load_kN": 55,
    "fatigue_load_limit_kN": 6.95,
    "max_rpm": 15000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 15000,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 25 mm shaft, SKF lists NUP2305-ECP as single-row caged cylindrical roller: 62 mm OD, 24 mm wide, Pu 6.95 kN, the catalogue lists 12,000 r/min thermal reference speed and 15,000 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 25 mm seat is about 2.56 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 55 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP2305-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "small pump rotor shafts",
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2305, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2305 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 24 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 24 mm-wide ring and concentrates load.",
      "The 64/55 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2305-ECP?",
        "a": "SKF NUP 2305 ECP is a single-row caged cylindrical roller bearing with 25 mm bore, 62 mm OD and 24 mm width per ISO 15. SKF lists C 64 kN, C0 55 kN, Pu 6.95 kN, reference speed 12,000 r/min and limiting speed 15,000 r/min, mass about 360 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2305-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2305-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2305-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×62×24 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2305",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×62×24 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2305-ECP",
      "SKF NUP 2305 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2306-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2306 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 83,
    "static_load_kN": 75,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 540,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2306 ECP is a single-row caged cylindrical roller bearing sized 30×72×27 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 0.90 (75 against 83 kN), and the Pu figure 9.65 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 11,000 r/min thermal reference speed and 12,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 30 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2306, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2306 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 27 mm-wide ring and concentrates load.",
      "The 83/75 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2306-ECP?",
        "a": "SKF NUP 2306 ECP is a single-row caged cylindrical roller bearing with 30 mm bore, 72 mm OD and 27 mm width per ISO 15. SKF lists C 83 kN, C0 75 kN, Pu 9.65 kN, reference speed 11,000 r/min and limiting speed 12,000 r/min, mass about 540 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2306-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2306-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2306-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×72×27 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2306",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×72×27 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2306-ECP",
      "SKF NUP 2306 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2307-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2307 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 106,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.7,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2307 ECP is a single-row caged cylindrical roller bearing sized 35×80×31 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 22.5 mm and the catalogue mass 760 g; at 106 kN dynamic rating this is roughly 3.03 kN of C per millimetre of bore before application factors. Fit practice for NUP2307-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2307, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2307 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 80 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 31 mm-wide ring and concentrates load.",
      "The 106/98 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2307-ECP?",
        "a": "SKF NUP 2307 ECP is a single-row caged cylindrical roller bearing with 35 mm bore, 80 mm OD and 31 mm width per ISO 15. SKF lists C 106 kN, C0 98 kN, Pu 12.7 kN, reference speed 9,500 r/min and limiting speed 11,000 r/min, mass about 760 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2307-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2307-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NJ2307-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×80×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2307",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×80×31 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2307-ECP",
      "SKF NUP 2307 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2308-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2308 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 129,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 980,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2308 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 40×90×33 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 980 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 129 kN and C0 120 kN, size the bearing on the 40×90 mm ISO 15 envelope and check the 15.3 kN Pu against the equivalent-load floor; the catalogue lists 8,000 r/min thermal reference speed and 9,500 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 40 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2308, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2308 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 33 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 33 mm-wide ring and concentrates load.",
      "The 129/120 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2308-ECP?",
        "a": "SKF NUP 2308 ECP is a single-row caged cylindrical roller bearing with 40 mm bore, 90 mm OD and 33 mm width per ISO 15. SKF lists C 129 kN, C0 120 kN, Pu 15.3 kN, reference speed 8,000 r/min and limiting speed 9,500 r/min, mass about 980 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2308-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2308-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2308",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 40×90×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2308-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×90×33 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2308",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×90×33 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2308-ECP",
      "SKF NUP 2308 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2309-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2309 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 160,
    "static_load_kN": 153,
    "fatigue_load_limit_kN": 20,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 1350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2309 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 45×100×36 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 1350 g. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP2309-ECP: the catalogue lists 7,500 r/min thermal reference speed and 8,500 r/min mechanical limiting speed. The mass entry 1350 g covers the complete catalogue execution. Fit practice for NUP2309-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2309, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2309 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 36 mm-wide ring and concentrates load.",
      "The 160/153 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2309-ECP?",
        "a": "SKF NUP 2309 ECP is a single-row caged cylindrical roller bearing with 45 mm bore, 100 mm OD and 36 mm width per ISO 15. SKF lists C 160 kN, C0 153 kN, Pu 20 kN, reference speed 7,500 r/min and limiting speed 8,500 r/min, mass about 1350 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2309-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2309-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2309",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 45×100×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2309-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×100×36 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2309",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×100×36 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2309-ECP",
      "SKF NUP 2309 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2310-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2310 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 186,
    "static_load_kN": 186,
    "fatigue_load_limit_kN": 24.5,
    "max_rpm": 8000,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 8000,
    "weight_g": 1750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2310 ECP is a single-row caged cylindrical roller bearing sized 50×110×40 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 50 mm seat is about 3.72 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 186 kN for static checks such as crane hook blocks standing under load. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 50 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2310, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2310 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 40 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 186/186 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2310-ECP?",
        "a": "SKF NUP 2310 ECP is a single-row caged cylindrical roller bearing with 50 mm bore, 110 mm OD and 40 mm width per ISO 15. SKF lists C 186 kN, C0 186 kN, Pu 24.5 kN, reference speed 6,700 r/min and limiting speed 8,000 r/min, mass about 1750 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2310-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2310-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2310",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 50×110×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2310-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×110×40 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2310",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×110×40 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2310-ECP",
      "SKF NUP 2310 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2311-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2311 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 232,
    "static_load_kN": 232,
    "fatigue_load_limit_kN": 30.5,
    "max_rpm": 7000,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 7000,
    "weight_g": 2300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2311 ECP is a single-row caged cylindrical roller bearing sized 55×120×43 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 32.5 mm and the catalogue mass 2300 g; at 232 kN dynamic rating this is roughly 4.22 kN of C per millimetre of bore before application factors. Fit practice for NUP2311-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2311, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2311 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 120 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 232/232 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2311-ECP?",
        "a": "SKF NUP 2311 ECP is a single-row caged cylindrical roller bearing with 55 mm bore, 120 mm OD and 43 mm width per ISO 15. SKF lists C 232 kN, C0 232 kN, Pu 30.5 kN, reference speed 6,000 r/min and limiting speed 7,000 r/min, mass about 2300 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2311-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2311-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2311",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 55×120×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2311-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×120×43 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2311",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×120×43 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2311-ECP",
      "SKF NUP 2311 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2312-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2312 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 260,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 34.5,
    "max_rpm": 6700,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6700,
    "weight_g": 2850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2312 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 60×130×46 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 2850 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 260 kN and C0 265 kN, size the bearing on the 60×130 mm ISO 15 envelope and check the 34.5 kN Pu against the equivalent-load floor; the catalogue lists 5,600 r/min thermal reference speed and 6,700 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 60 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2312, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2312 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 46 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 260/265 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2312-ECP?",
        "a": "SKF NUP 2312 ECP is a single-row caged cylindrical roller bearing with 60 mm bore, 130 mm OD and 46 mm width per ISO 15. SKF lists C 260 kN, C0 265 kN, Pu 34.5 kN, reference speed 5,600 r/min and limiting speed 6,700 r/min, mass about 2850 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2312-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2312-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2312",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 60×130×46 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2312-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×130×46 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2312",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×130×46 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2312-ECP",
      "SKF NUP 2312 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2313-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2313 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 285,
    "static_load_kN": 290,
    "fatigue_load_limit_kN": 38,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 3450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2313 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 65×140×48 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 3450 g. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Speed planning for NUP2313-ECP: the catalogue lists 5,300 r/min thermal reference speed and 6,000 r/min mechanical limiting speed. The mass entry 3450 g covers the complete catalogue execution. Fit practice for NUP2313-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2313, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2313 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 285/290 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2313-ECP?",
        "a": "SKF NUP 2313 ECP is a single-row caged cylindrical roller bearing with 65 mm bore, 140 mm OD and 48 mm width per ISO 15. SKF lists C 285 kN, C0 290 kN, Pu 38 kN, reference speed 5,300 r/min and limiting speed 6,000 r/min, mass about 3450 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2313-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2313-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2313",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 65×140×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2313-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×48 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2313-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×48 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2313-ECP",
      "SKF NUP 2313 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2314-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2314 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 315,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 41.5,
    "max_rpm": 5600,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5600,
    "weight_g": 4150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2314 ECP resolves to a 70×150×51 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 70 mm seat is about 4.50 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 325 kN for static checks such as crane hook blocks standing under load. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 70 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2314, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2314 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 150 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 315/325 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2314-ECP?",
        "a": "SKF NUP 2314 ECP is a single-row caged cylindrical roller bearing with 70 mm bore, 150 mm OD and 51 mm width per ISO 15. SKF lists C 315 kN, C0 325 kN, Pu 41.5 kN, reference speed 4,800 r/min and limiting speed 5,600 r/min, mass about 4150 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2314-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2314-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2314",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 70×150×51 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2314-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×51 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2314-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×51 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2314-ECP",
      "SKF NUP 2314 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2315-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2315 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 380,
    "static_load_kN": 400,
    "fatigue_load_limit_kN": 50,
    "max_rpm": 5300,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5300,
    "weight_g": 5100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2315-ECP is the 75 mm bore entry in the NUP2300 range: a 75×160×55 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 380 kN / C0 400 kN. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.05 (400 against 380 kN), and the Pu figure 50 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 4,500 r/min thermal reference speed and 5,300 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2315, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2315 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 55 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 380/400 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2315-ECP?",
        "a": "SKF NUP 2315 ECP is a single-row caged cylindrical roller bearing with 75 mm bore, 160 mm OD and 55 mm width per ISO 15. SKF lists C 380 kN, C0 400 kN, Pu 50 kN, reference speed 4,500 r/min and limiting speed 5,300 r/min, mass about 5100 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2315-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2315-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2315",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 75×160×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2315-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×55 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2315-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×55 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2315-ECP",
      "SKF NUP 2315 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2316-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2316 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 415,
    "static_load_kN": 440,
    "fatigue_load_limit_kN": 55,
    "max_rpm": 5000,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 5000,
    "weight_g": 6000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP2316-ECP is the 80 mm bore entry in the NUP2300 range: a 80×170×58 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 415 kN / C0 440 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 45.0 mm and the catalogue mass 6000 g; at 415 kN dynamic rating this is roughly 5.19 kN of C per millimetre of bore before application factors. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 80 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2316, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2316 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 415/440 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2316-ECP?",
        "a": "SKF NUP 2316 ECP is a single-row caged cylindrical roller bearing with 80 mm bore, 170 mm OD and 58 mm width per ISO 15. SKF lists C 415 kN, C0 440 kN, Pu 55 kN, reference speed 4,300 r/min and limiting speed 5,000 r/min, mass about 6000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2316-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2316-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2316",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 80×170×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2316-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2316-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×58 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2316-ECP",
      "SKF NUP 2316 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2317-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2317 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 455,
    "static_load_kN": 490,
    "fatigue_load_limit_kN": 60,
    "max_rpm": 4800,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4800,
    "weight_g": 7000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 85 mm shaft, SKF lists NUP2317-ECP as single-row caged cylindrical roller: 180 mm OD, 60 mm wide, Pu 60 kN, the catalogue lists 4,000 r/min thermal reference speed and 4,800 r/min mechanical limiting speed. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 455 kN and C0 490 kN, size the bearing on the 85×180 mm ISO 15 envelope and check the 60 kN Pu against the equivalent-load floor; the catalogue lists 4,000 r/min thermal reference speed and 4,800 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2317, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2317 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 455/490 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2317-ECP?",
        "a": "SKF NUP 2317 ECP is a single-row caged cylindrical roller bearing with 85 mm bore, 180 mm OD and 60 mm width per ISO 15. SKF lists C 455 kN, C0 490 kN, Pu 60 kN, reference speed 4,000 r/min and limiting speed 4,800 r/min, mass about 7000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2317-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2317-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2317",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×180×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2317-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×60 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2317-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×60 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2317-ECP",
      "SKF NUP 2317 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2318-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2318 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 500,
    "static_load_kN": 540,
    "fatigue_load_limit_kN": 65.5,
    "max_rpm": 4500,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4500,
    "weight_g": 8250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 90 mm shaft, SKF lists NUP2318-ECP as single-row caged cylindrical roller: 190 mm OD, 64 mm wide, Pu 65.5 kN, the catalogue lists 3,800 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 90 mm seat is about 5.56 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 540 kN for static checks such as crane hook blocks standing under load. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 90 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2318, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2318 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 500/540 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2318-ECP?",
        "a": "SKF NUP 2318 ECP is a single-row caged cylindrical roller bearing with 90 mm bore, 190 mm OD and 64 mm width per ISO 15. SKF lists C 500 kN, C0 540 kN, Pu 65.5 kN, reference speed 3,800 r/min and limiting speed 4,500 r/min, mass about 8250 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2318-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2318-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2318",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 90×190×64 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2318-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×64 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2318-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×64 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2318-ECP",
      "SKF NUP 2318 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2319-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2319 ECJ",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 530,
    "static_load_kN": 585,
    "fatigue_load_limit_kN": 69.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4300,
    "weight_g": 9700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2319 ECJ resolves to a 95×200×67 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Selection arithmetic: C0/C ≈ 1.10 (585 against 530 kN), and the Pu figure 69.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,600 r/min thermal reference speed and 4,300 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2319, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2319 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 530/585 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2319-ECJ?",
        "a": "SKF NUP 2319 ECJ is a single-row caged cylindrical roller bearing with 95 mm bore, 200 mm OD and 67 mm width per ISO 15. SKF lists C 530 kN, C0 585 kN, Pu 69.5 kN, reference speed 3,600 r/min and limiting speed 4,300 r/min, mass about 9700 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2319-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2319-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2319",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 95×200×67 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2319-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×67 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2319-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×67 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2319-ECJ",
      "SKF NUP 2319 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP232-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 232 ECM",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 585,
    "static_load_kN": 680,
    "fatigue_load_limit_kN": 72,
    "max_rpm": 2600,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2600,
    "weight_g": 15500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 232 ECM resolves to a 160×290×48 mm single-row caged cylindrical roller bearing (dimension series 2 (light-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Speed planning for NUP232-ECM: the catalogue lists 2,400 r/min thermal reference speed and 2,600 r/min mechanical limiting speed. The mass entry 15500 g covers the complete catalogue execution. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 160 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 232, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 232 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 48 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 585/680 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP232-ECM?",
        "a": "SKF NUP 232 ECM is a single-row caged cylindrical roller bearing with 160 mm bore, 290 mm OD and 48 mm width per ISO 15. SKF lists C 585 kN, C0 680 kN, Pu 72 kN, reference speed 2,400 r/min and limiting speed 2,600 r/min, mass about 15500 g."
      },
      {
        "q": "What does the NUP designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP232-ECM take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP232-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP232",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 160×290×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ232-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×290×48 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU232-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 160×290×48 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP232-ECM",
      "SKF NUP 232 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2320-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2320 ECJ",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 670,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 85,
    "max_rpm": 3800,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3800,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2320 ECJ is a single-row caged cylindrical roller bearing sized 100×215×73 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECJ: the E-design execution with a pressed sheet-steel window cage, for positions where polymer cages are temperature- or lubricant-limited. Selection arithmetic: C0/C ≈ 1.10 (735 against 670 kN), and the Pu figure 85 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,200 r/min thermal reference speed and 3,800 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2320, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2320 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 73 mm-wide ring and concentrates load.",
      "The 670/735 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2320-ECJ?",
        "a": "SKF NUP 2320 ECJ is a single-row caged cylindrical roller bearing with 100 mm bore, 215 mm OD and 73 mm width per ISO 15. SKF lists C 670 kN, C0 735 kN, Pu 85 kN, reference speed 3,200 r/min and limiting speed 3,800 r/min, mass about 12500 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2320-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2320-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2320",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 100×215×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2320-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×73 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2320-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×73 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2320-ECJ",
      "SKF NUP 2320 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2322-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2322 ECP",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 780,
    "static_load_kN": 900,
    "fatigue_load_limit_kN": 102,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 17500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 2322 ECP is a single-row caged cylindrical roller bearing sized 110×240×80 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 780 kN and C0 900 kN, size the bearing on the 110×240 mm ISO 15 envelope and check the 102 kN Pu against the equivalent-load floor; the catalogue lists 3,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 110 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2322, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2322 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 780/900 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2322-ECP?",
        "a": "SKF NUP 2322 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 240 mm OD and 80 mm width per ISO 15. SKF lists C 780 kN, C0 900 kN, Pu 102 kN, reference speed 3,000 r/min and limiting speed 3,400 r/min, mass about 17500 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2322-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2322-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2322",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×240×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×80 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2322-ECP",
      "SKF NUP 2322 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2324-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2324 ECML",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 915,
    "static_load_kN": 1040,
    "fatigue_load_limit_kN": 116,
    "max_rpm": 5000,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 5000,
    "weight_g": 23500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 2324 ECML resolves to a 120×260×86 mm single-row caged cylindrical roller bearing (dimension series 23 (medium-section, wide)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The radial section height is 70.0 mm and the catalogue mass 23500 g; at 915 kN dynamic rating this is roughly 7.63 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2324, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2324 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 260 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 915/1040 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2324-ECML?",
        "a": "SKF NUP 2324 ECML is a single-row caged cylindrical roller bearing with 120 mm bore, 260 mm OD and 86 mm width per ISO 15. SKF lists C 915 kN, C0 1040 kN, Pu 116 kN, reference speed 2,800 r/min and limiting speed 5,000 r/min, mass about 23500 g."
      },
      {
        "q": "What does the NUP designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2324-ECML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2324-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2324",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×260×86 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2324-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×86 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2324-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×86 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2324-ECML",
      "SKF NUP 2324 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2326-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2326 ECML",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 93,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1060,
    "static_load_kN": 1250,
    "fatigue_load_limit_kN": 137,
    "max_rpm": 4500,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 4500,
    "weight_g": 29500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 130 mm shaft, SKF lists NUP2326-ECML as single-row caged cylindrical roller: 280 mm OD, 93 mm wide, Pu 137 kN, the catalogue lists 2,400 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1060 kN and C0 1250 kN, size the bearing on the 130×280 mm ISO 15 envelope and check the 137 kN Pu against the equivalent-load floor; the catalogue lists 2,400 r/min thermal reference speed and 4,500 r/min mechanical limiting speed. Fit practice for NUP2326-ECML: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2326, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2326 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 93 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 280 mm raceway.",
      "The 1060/1250 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2326-ECML?",
        "a": "SKF NUP 2326 ECML is a single-row caged cylindrical roller bearing with 130 mm bore, 280 mm OD and 93 mm width per ISO 15. SKF lists C 1060 kN, C0 1250 kN, Pu 137 kN, reference speed 2,400 r/min and limiting speed 4,500 r/min, mass about 29500 g."
      },
      {
        "q": "What does the NUP designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2326-ECML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2326-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2326",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×280×93 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2326-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×93 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2326-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×93 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2326-ECML",
      "SKF NUP 2326 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP2328-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 2328 ECML",
    "series": "NUP2300-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1200,
    "static_load_kN": 1430,
    "fatigue_load_limit_kN": 150,
    "max_rpm": 4300,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 4300,
    "weight_g": 37000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 2328 ECML denotes a single-row caged cylindrical roller bearing on the ISO 15 140×300×102 mm envelope, dimension series 23 (medium-section, wide), with catalogue mass 37000 g. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Load-per-bore for the 140 mm seat is about 8.57 kN/mm, typical of dimension series 23 (medium-section, wide); use C0 1430 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP2328-ECML: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2328, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2328 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 300 mm raceway.",
      "The 1200/1430 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP2328-ECML?",
        "a": "SKF NUP 2328 ECML is a single-row caged cylindrical roller bearing with 140 mm bore, 300 mm OD and 102 mm width per ISO 15. SKF lists C 1200 kN, C0 1430 kN, Pu 150 kN, reference speed 2,400 r/min and limiting speed 4,300 r/min, mass about 37000 g."
      },
      {
        "q": "What does the NUP designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP2328-ECML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP2328-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP2328",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×300×102 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ2328-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×102 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU2328-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×102 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP2328-ECML",
      "SKF NUP 2328 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP238-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 238 ECML",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 800,
    "static_load_kN": 965,
    "fatigue_load_limit_kN": 98,
    "max_rpm": 3400,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 3400,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 190 mm shaft, SKF lists NUP238-ECML as single-row caged cylindrical roller: 340 mm OD, 55 mm wide, Pu 98 kN, the catalogue lists 2,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Load-per-bore for the 190 mm seat is about 4.21 kN/mm, typical of dimension series 2 (light-section ISO 15 envelope); use C0 965 kN for static checks such as crane hook blocks standing under load. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 238, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 238 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 800/965 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP238-ECML?",
        "a": "SKF NUP 238 ECML is a single-row caged cylindrical roller bearing with 190 mm bore, 340 mm OD and 55 mm width per ISO 15. SKF lists C 800 kN, C0 965 kN, Pu 98 kN, reference speed 2,000 r/min and limiting speed 3,400 r/min, mass about 22500 g."
      },
      {
        "q": "What does the NUP designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP238-ECML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP238-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP238",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 190×340×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ238-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×340×55 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU238-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 190×340×55 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP238-ECML",
      "SKF NUP 238 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP244-ECML",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 244 ECML",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 220,
    "D_mm": 400,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1060,
    "static_load_kN": 1290,
    "fatigue_load_limit_kN": 125,
    "max_rpm": 3000,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 3000,
    "weight_g": 37500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP244-ECML is the 220 mm bore entry in the NUP200 range: a 220×400×65 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1060 kN / C0 1290 kN. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Speed planning for NUP244-ECML: the catalogue lists 1,700 r/min thermal reference speed and 3,000 r/min mechanical limiting speed. The mass entry 37500 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 244, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 244 ECML and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 400 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 1060/1290 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP244-ECML?",
        "a": "SKF NUP 244 ECML is a single-row caged cylindrical roller bearing with 220 mm bore, 400 mm OD and 65 mm width per ISO 15. SKF lists C 1060 kN, C0 1290 kN, Pu 125 kN, reference speed 1,700 r/min and limiting speed 3,000 r/min, mass about 37500 g."
      },
      {
        "q": "What does the NUP designation and ECML suffix mean?",
        "a": "The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP244-ECML take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP244-ECML compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP244",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 220×400×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ244-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×65 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU244-ECML",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 220×400×65 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP244-ECML",
      "SKF NUP 244 ECML"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP248-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 248 MA",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 952,
    "static_load_kN": 1370,
    "fatigue_load_limit_kN": 129,
    "max_rpm": 2200,
    "reference_speed_rpm": 1600,
    "limiting_speed_rpm": 2200,
    "weight_g": 53000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP248-MA is the 240 mm bore entry in the NUP200 range: a 240×440×72 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 952 kN / C0 1370 kN. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix MA: the basic (non-E) MA execution with a machined brass cage, standard for the larger and earlier-design sizes. The radial section height is 100.0 mm and the catalogue mass 53000 g; at 952 kN dynamic rating this is roughly 3.97 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 248, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 248 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 440 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 72 mm-wide ring and concentrates load.",
      "The 952/1370 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP248-MA?",
        "a": "SKF NUP 248 MA is a single-row caged cylindrical roller bearing with 240 mm bore, 440 mm OD and 72 mm width per ISO 15. SKF lists C 952 kN, C0 1370 kN, Pu 129 kN, reference speed 1,600 r/min and limiting speed 2,200 r/min, mass about 53000 g."
      },
      {
        "q": "What does the NUP designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP248-MA take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP248-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP248",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ248-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 240×440×72 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU248-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 240×440×72 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP248-MA",
      "SKF NUP 248 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP252-MA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 252 MA",
    "series": "NUP200-series",
    "type": "cylindrical_roller",
    "d_mm": 260,
    "D_mm": 480,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1170,
    "static_load_kN": 1700,
    "fatigue_load_limit_kN": 150,
    "max_rpm": 2000,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 2000,
    "weight_g": 72000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP252-MA is the 260 mm bore entry in the NUP200 range: a 260×480×80 mm single-row caged cylindrical roller bearing with a one-piece machined brass cage, rated C 1170 kN / C0 1700 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Speed planning for NUP252-MA: the catalogue lists 1,400 r/min thermal reference speed and 2,000 r/min mechanical limiting speed. The mass entry 72000 g covers the complete catalogue execution. Fit practice for NUP252-MA: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 2 (light-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 252, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 252 MA and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 80 mm-wide ring and concentrates load.",
      "The 1170/1700 kN ratings are SKF catalogue 17000 (2018) values for the MA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP252-MA?",
        "a": "SKF NUP 252 MA is a single-row caged cylindrical roller bearing with 260 mm bore, 480 mm OD and 80 mm width per ISO 15. SKF lists C 1170 kN, C0 1700 kN, Pu 150 kN, reference speed 1,400 r/min and limiting speed 2,000 r/min, mass about 72000 g."
      },
      {
        "q": "What does the NUP designation and MA suffix mean?",
        "a": "The MA suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP252-MA take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP252-MA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP252",
        "equiv_brand": "NTN",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NJ252-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 260×480×80 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU252-MA",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 260×480×80 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP252-MA",
      "SKF NUP 252 MA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP29-530-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 29/530 ECMA",
    "series": "NUP2900-series",
    "type": "cylindrical_roller",
    "d_mm": 530,
    "D_mm": 710,
    "B_mm": 106,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2380,
    "static_load_kN": 5000,
    "fatigue_load_limit_kN": 390,
    "max_rpm": 1100,
    "reference_speed_rpm": 850,
    "limiting_speed_rpm": 1100,
    "weight_g": 130000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 29/530 ECMA resolves to a 530×710×106 mm single-row caged cylindrical roller bearing (dimension series 29 (compact OD, normal width)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 2380 kN and C0 5000 kN, size the bearing on the 530×710 mm ISO 15 envelope and check the 390 kN Pu against the equivalent-load floor; the catalogue lists 850 r/min thermal reference speed and 1,100 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 29/530, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 29/530 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 710 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 710 mm raceway.",
      "The 2380/5000 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP29-530-ECMA?",
        "a": "SKF NUP 29/530 ECMA is a single-row caged cylindrical roller bearing with 530 mm bore, 710 mm OD and 106 mm width per ISO 15. SKF lists C 2380 kN, C0 5000 kN, Pu 390 kN, reference speed 850 r/min and limiting speed 1,100 r/min, mass about 130000 g."
      },
      {
        "q": "What does the NUP designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP29-530-ECMA take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP29-530-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP29-530-ECMA",
      "SKF NUP 29/530 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP304-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 304 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 35.5,
    "static_load_kN": 26,
    "fatigue_load_limit_kN": 3.25,
    "max_rpm": 18000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 18000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 304 ECP is a single-row caged cylindrical roller bearing sized 20×52×15 mm — a dimension series 3 (medium-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Load-per-bore for the 20 mm seat is about 1.77 kN/mm, typical of dimension series 3 (medium-section ISO 15 envelope); use C0 26 kN for static checks such as crane hook blocks standing under load. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 20 mm seat normally takes a k5 interference with an H7 housing bore when the inner ring rotates.",
    "applications": [
      "small pump rotor shafts",
      "small industrial electric-motor shafts",
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 304, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 304 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 15 mm-wide ring and concentrates load.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 15 mm-wide ring and concentrates load.",
      "The 35.5/26 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP304-ECP?",
        "a": "SKF NUP 304 ECP is a single-row caged cylindrical roller bearing with 20 mm bore, 52 mm OD and 15 mm width per ISO 15. SKF lists C 35.5 kN, C0 26 kN, Pu 3.25 kN, reference speed 15,000 r/min and limiting speed 18,000 r/min, mass about 160 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP304-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP304-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N304-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×15 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ304-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×15 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU304",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 20×52×15 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP304-ECP",
      "SKF NUP 304 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP305-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 305 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 46.5,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 4.55,
    "max_rpm": 15000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 15000,
    "weight_g": 250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 305 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 25×62×17 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 250 g. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 18.5 mm and the catalogue mass 250 g; at 46.5 kN dynamic rating this is roughly 1.86 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "light gearbox layshafts",
      "motor-cycle and small-engine transmissions",
      "appliance and fan armature shafts",
      "small pump rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 305, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 305 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 62 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 17 mm-wide ring and concentrates load.",
      "The 46.5/36.5 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP305-ECP?",
        "a": "SKF NUP 305 ECP is a single-row caged cylindrical roller bearing with 25 mm bore, 62 mm OD and 17 mm width per ISO 15. SKF lists C 46.5 kN, C0 36.5 kN, Pu 4.55 kN, reference speed 12,000 r/min and limiting speed 15,000 r/min, mass about 250 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP305-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP305-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N305-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×62×17 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ305-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×62×17 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU305",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 25×62×17 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP305-ECP",
      "SKF NUP 305 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP306-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 306 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 58.5,
    "static_load_kN": 48,
    "fatigue_load_limit_kN": 6.2,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 306 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 30×72×19 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 380 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 21.0 mm and the catalogue mass 380 g; at 58.5 kN dynamic rating this is roughly 1.95 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 306, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 306 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 19 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 58.5/48 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP306-ECP?",
        "a": "SKF NUP 306 ECP is a single-row caged cylindrical roller bearing with 30 mm bore, 72 mm OD and 19 mm width per ISO 15. SKF lists C 58.5 kN, C0 48 kN, Pu 6.2 kN, reference speed 11,000 r/min and limiting speed 12,000 r/min, mass about 380 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP306-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP306-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N306-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×72×19 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ306-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×72×19 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU306",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 30×72×19 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP306-ECP",
      "SKF NUP 306 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP307-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 307 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 75,
    "static_load_kN": 63,
    "fatigue_load_limit_kN": 8.15,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 490,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 307 ECP resolves to a 35×80×21 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. With C 75 kN and C0 63 kN, size the bearing on the 35×80 mm ISO 15 envelope and check the 8.15 kN Pu against the equivalent-load floor; the catalogue lists 9,500 r/min thermal reference speed and 11,000 r/min mechanical limiting speed. Fit practice for NUP307-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "smearing (microwelding) on roller surfaces during skid starts with insufficient minimum load"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 307, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 307 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 75/63 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP307-ECP?",
        "a": "SKF NUP 307 ECP is a single-row caged cylindrical roller bearing with 35 mm bore, 80 mm OD and 21 mm width per ISO 15. SKF lists C 75 kN, C0 63 kN, Pu 8.15 kN, reference speed 9,500 r/min and limiting speed 11,000 r/min, mass about 490 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP307-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP307-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "N307-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×80×21 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ307-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×80×21 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU307",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 35×80×21 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP307-ECP",
      "SKF NUP 307 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP308-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 308 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 93,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 10.2,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 680,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 308 ECP resolves to a 40×90×23 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP308-ECP: the catalogue lists 8,000 r/min thermal reference speed and 9,500 r/min mechanical limiting speed. The mass entry 680 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 308, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 308 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 90 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 93/78 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP308-ECP?",
        "a": "SKF NUP 308 ECP is a single-row caged cylindrical roller bearing with 40 mm bore, 90 mm OD and 23 mm width per ISO 15. SKF lists C 93 kN, C0 78 kN, Pu 10.2 kN, reference speed 8,000 r/min and limiting speed 9,500 r/min, mass about 680 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP308-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP308-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP308",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N308-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×90×23 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ308-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×90×23 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU308",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 40×90×23 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP308-ECP",
      "SKF NUP 308 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP309-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 309 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 112,
    "static_load_kN": 100,
    "fatigue_load_limit_kN": 12.9,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 930,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP309-ECP is the 45 mm bore entry in the NUP300 range: a 45×100×25 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 112 kN / C0 100 kN. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Load-per-bore for the 45 mm seat is about 2.49 kN/mm, typical of dimension series 3 (medium-section ISO 15 envelope); use C0 100 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP309-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "conveyor drive-pulley shafts",
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 309, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 309 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 25 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 112/100 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP309-ECP?",
        "a": "SKF NUP 309 ECP is a single-row caged cylindrical roller bearing with 45 mm bore, 100 mm OD and 25 mm width per ISO 15. SKF lists C 112 kN, C0 100 kN, Pu 12.9 kN, reference speed 7,500 r/min and limiting speed 8,500 r/min, mass about 930 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP309-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP309-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP309",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N309-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×100×25 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ309-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×100×25 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU309",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 45×100×25 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP309-ECP",
      "SKF NUP 309 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP310-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 310 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 127,
    "static_load_kN": 112,
    "fatigue_load_limit_kN": 15,
    "max_rpm": 8000,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 8000,
    "weight_g": 1150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 310 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 50×110×27 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 1150 g. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 0.88 (112 against 127 kN), and the Pu figure 15 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 6,700 r/min thermal reference speed and 8,000 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "medium industrial gearbox shafts",
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "false brinelling on standby machines exposed to external vibration"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 310, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 310 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 110 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 110 mm raceway.",
      "The 127/112 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP310-ECP?",
        "a": "SKF NUP 310 ECP is a single-row caged cylindrical roller bearing with 50 mm bore, 110 mm OD and 27 mm width per ISO 15. SKF lists C 127 kN, C0 112 kN, Pu 15 kN, reference speed 6,700 r/min and limiting speed 8,000 r/min, mass about 1150 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP310-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP310-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP310",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N310-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×110×27 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ310-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×110×27 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU310",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 50×110×27 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP310-ECP",
      "SKF NUP 310 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP311-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 311 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 156,
    "static_load_kN": 143,
    "fatigue_load_limit_kN": 18.6,
    "max_rpm": 7000,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 7000,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 311 ECP resolves to a 55×120×29 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 32.5 mm and the catalogue mass 1500 g; at 156 kN dynamic rating this is roughly 2.84 kN of C per millimetre of bore before application factors. Fit practice for NUP311-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "electric-motor shafts in pumps and fans",
      "compressor crank and rotor shafts",
      "machine-tool radial spindle supports",
      "conveyor drive-pulley shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 311, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 311 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 29 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 120 mm raceway.",
      "The 156/143 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP311-ECP?",
        "a": "SKF NUP 311 ECP is a single-row caged cylindrical roller bearing with 55 mm bore, 120 mm OD and 29 mm width per ISO 15. SKF lists C 156 kN, C0 143 kN, Pu 18.6 kN, reference speed 6,000 r/min and limiting speed 7,000 r/min, mass about 1500 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP311-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP311-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP311",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N311-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×120×29 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ311-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×120×29 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU311",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 55×120×29 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP311-ECP",
      "SKF NUP 311 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP312-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 312 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 173,
    "static_load_kN": 160,
    "fatigue_load_limit_kN": 21.2,
    "max_rpm": 6700,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6700,
    "weight_g": 1900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 312 ECP resolves to a 60×130×31 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. Speed planning for NUP312-ECP: the catalogue lists 5,600 r/min thermal reference speed and 6,700 r/min mechanical limiting speed. The mass entry 1900 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 312, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 312 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 130 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 130 mm raceway.",
      "The 173/160 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP312-ECP?",
        "a": "SKF NUP 312 ECP is a single-row caged cylindrical roller bearing with 60 mm bore, 130 mm OD and 31 mm width per ISO 15. SKF lists C 173 kN, C0 160 kN, Pu 21.2 kN, reference speed 5,600 r/min and limiting speed 6,700 r/min, mass about 1900 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP312-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP312-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP312",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N312-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×130×31 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ312-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×130×31 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU312",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 60×130×31 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP312-ECP",
      "SKF NUP 312 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP313-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 313 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 212,
    "static_load_kN": 196,
    "fatigue_load_limit_kN": 25.5,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 2350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP313-ECP is the 65 mm bore entry in the NUP300 range: a 65×140×33 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 212 kN / C0 196 kN. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Load-per-bore for the 65 mm seat is about 3.26 kN/mm, typical of dimension series 3 (medium-section ISO 15 envelope); use C0 196 kN for static checks such as crane hook blocks standing under load. Fit practice for NUP313-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 313, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 313 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 33 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 140 mm raceway.",
      "The 212/196 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP313-ECP?",
        "a": "SKF NUP 313 ECP is a single-row caged cylindrical roller bearing with 65 mm bore, 140 mm OD and 33 mm width per ISO 15. SKF lists C 212 kN, C0 196 kN, Pu 25.5 kN, reference speed 5,300 r/min and limiting speed 6,000 r/min, mass about 2350 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP313-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP313-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP313",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N313-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×33 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ313-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×33 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU313",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 65×140×33 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP313-ECP",
      "SKF NUP 313 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP314-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 314 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 236,
    "static_load_kN": 228,
    "fatigue_load_limit_kN": 29,
    "max_rpm": 5600,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5600,
    "weight_g": 2850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 70 mm shaft, SKF lists NUP314-ECP as single-row caged cylindrical roller: 150 mm OD, 35 mm wide, Pu 29 kN, the catalogue lists 4,800 r/min thermal reference speed and 5,600 r/min mechanical limiting speed. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 0.97 (228 against 236 kN), and the Pu figure 29 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 4,800 r/min thermal reference speed and 5,600 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 70 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 314, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 314 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 150 mm raceway.",
      "The 236/228 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP314-ECP?",
        "a": "SKF NUP 314 ECP is a single-row caged cylindrical roller bearing with 70 mm bore, 150 mm OD and 35 mm width per ISO 15. SKF lists C 236 kN, C0 228 kN, Pu 29 kN, reference speed 4,800 r/min and limiting speed 5,600 r/min, mass about 2850 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP314-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP314-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP314",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 70×150×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N314-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×35 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ314-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×35 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU314",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 70×150×35 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP314-ECP",
      "SKF NUP 314 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP315-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 315 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 280,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 33.5,
    "max_rpm": 5300,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5300,
    "weight_g": 3450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 75 mm shaft, SKF lists NUP315-ECP as single-row caged cylindrical roller: 160 mm OD, 37 mm wide, Pu 33.5 kN, the catalogue lists 4,500 r/min thermal reference speed and 5,300 r/min mechanical limiting speed. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The radial section height is 42.5 mm and the catalogue mass 3450 g; at 280 kN dynamic rating this is roughly 3.73 kN of C per millimetre of bore before application factors. Fit practice for NUP315-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 315, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 315 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 160 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 160 mm raceway.",
      "The 280/265 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP315-ECP?",
        "a": "SKF NUP 315 ECP is a single-row caged cylindrical roller bearing with 75 mm bore, 160 mm OD and 37 mm width per ISO 15. SKF lists C 280 kN, C0 265 kN, Pu 33.5 kN, reference speed 4,500 r/min and limiting speed 5,300 r/min, mass about 3450 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP315-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP315-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP315",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N315-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×37 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ315-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×37 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU315",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 75×160×37 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP315-ECP",
      "SKF NUP 315 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP316-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 316 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 300,
    "static_load_kN": 290,
    "fatigue_load_limit_kN": 36,
    "max_rpm": 5000,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 5000,
    "weight_g": 4100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 316 ECP is a single-row caged cylindrical roller bearing sized 80×170×39 mm — a dimension series 3 (medium-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. With C 300 kN and C0 290 kN, size the bearing on the 80×170 mm ISO 15 envelope and check the 36 kN Pu against the equivalent-load floor; the catalogue lists 4,300 r/min thermal reference speed and 5,000 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 80 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "hard-particle indentation of the raceway in unfiltered oil systems"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 316, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 316 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 39 mm-wide ring and concentrates load.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 170 mm raceway.",
      "The 300/290 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP316-ECP?",
        "a": "SKF NUP 316 ECP is a single-row caged cylindrical roller bearing with 80 mm bore, 170 mm OD and 39 mm width per ISO 15. SKF lists C 300 kN, C0 290 kN, Pu 36 kN, reference speed 4,300 r/min and limiting speed 5,000 r/min, mass about 4100 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP316-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP316-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP316",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N316-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×39 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ316-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×39 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU316",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 80×170×39 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP316-ECP",
      "SKF NUP 316 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP317-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 317 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 41,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 340,
    "static_load_kN": 335,
    "fatigue_load_limit_kN": 41.5,
    "max_rpm": 4800,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4800,
    "weight_g": 4900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 317 ECP is a single-row caged cylindrical roller bearing sized 85×180×41 mm — a dimension series 3 (medium-section ISO 15 envelope), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECP: the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP317-ECP: the catalogue lists 4,000 r/min thermal reference speed and 4,800 r/min mechanical limiting speed. The mass entry 4900 g covers the complete catalogue execution. Fit practice for NUP317-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "electrical pitting on VFD-driven shafts without grounding protection"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 317, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 317 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 180 mm raceway.",
      "The 340/335 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP317-ECP?",
        "a": "SKF NUP 317 ECP is a single-row caged cylindrical roller bearing with 85 mm bore, 180 mm OD and 41 mm width per ISO 15. SKF lists C 340 kN, C0 335 kN, Pu 41.5 kN, reference speed 4,000 r/min and limiting speed 4,800 r/min, mass about 4900 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP317-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP317-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP317",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N317-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×41 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ317-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×41 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU317",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 85×180×41 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP317-ECP",
      "SKF NUP 317 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP318-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 318 ECJ",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 365,
    "static_load_kN": 360,
    "fatigue_load_limit_kN": 43,
    "max_rpm": 4500,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4500,
    "weight_g": 5550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP318-ECJ is the 90 mm bore entry in the NUP300 range: a 90×190×43 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 365 kN / C0 360 kN. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Load-per-bore for the 90 mm seat is about 4.06 kN/mm, typical of dimension series 3 (medium-section ISO 15 envelope); use C0 360 kN for static checks such as crane hook blocks standing under load. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 90 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 318, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 318 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 190 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 190 mm raceway.",
      "The 365/360 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP318-ECJ?",
        "a": "SKF NUP 318 ECJ is a single-row caged cylindrical roller bearing with 90 mm bore, 190 mm OD and 43 mm width per ISO 15. SKF lists C 365 kN, C0 360 kN, Pu 43 kN, reference speed 3,800 r/min and limiting speed 4,500 r/min, mass about 5550 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP318-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP318-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP318",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N318-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×43 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ318-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×43 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU318",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 90×190×43 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP318-ECJ",
      "SKF NUP 318 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP319-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 319 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 390,
    "static_load_kN": 390,
    "fatigue_load_limit_kN": 46.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4300,
    "weight_g": 6300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 319 ECP resolves to a 95×200×45 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 52.5 mm and the catalogue mass 6300 g; at 390 kN dynamic rating this is roughly 4.11 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 319, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 319 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 200 mm raceway.",
      "The 390/390 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP319-ECP?",
        "a": "SKF NUP 319 ECP is a single-row caged cylindrical roller bearing with 95 mm bore, 200 mm OD and 45 mm width per ISO 15. SKF lists C 390 kN, C0 390 kN, Pu 46.5 kN, reference speed 3,600 r/min and limiting speed 4,300 r/min, mass about 6300 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP319-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP319-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP319",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N319-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×45 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ319-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×45 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU319",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 95×200×45 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP319-ECP",
      "SKF NUP 319 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP320-ECJ",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 320 ECJ",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 47,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 450,
    "static_load_kN": 440,
    "fatigue_load_limit_kN": 51,
    "max_rpm": 3800,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3800,
    "weight_g": 7700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 320 ECJ resolves to a 100×215×47 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. The radial section height is 57.5 mm and the catalogue mass 7700 g; at 450 kN dynamic rating this is roughly 4.50 kN of C per millimetre of bore before application factors. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large pump and blower rotors",
      "rolling-mill auxiliary drive shafts",
      "paper-machine press rolls",
      "cement-plant conveyor drives"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 320, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 320 ECJ and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 47 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 450/440 kN ratings are SKF catalogue 17000 (2018) values for the ECJ execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP320-ECJ?",
        "a": "SKF NUP 320 ECJ is a single-row caged cylindrical roller bearing with 100 mm bore, 215 mm OD and 47 mm width per ISO 15. SKF lists C 450 kN, C0 440 kN, Pu 51 kN, reference speed 3,200 r/min and limiting speed 3,800 r/min, mass about 7700 g."
      },
      {
        "q": "What does the NUP designation and ECJ suffix mean?",
        "a": "The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP320-ECJ take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP320-ECJ compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP320",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N320-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ320-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU320",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP320-ECJ",
      "SKF NUP 320 ECJ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP322-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 322 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 530,
    "static_load_kN": 540,
    "fatigue_load_limit_kN": 61,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 322 ECP denotes a single-row caged cylindrical roller bearing on the ISO 15 110×240×50 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 10500 g. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP322-ECP: the catalogue lists 3,000 r/min thermal reference speed and 3,400 r/min mechanical limiting speed. The mass entry 10500 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "paper-machine press rolls",
      "cement-plant conveyor drives",
      "heavy gearbox and pinion shafts",
      "large pump and blower rotors"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 322, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 322 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 240 mm raceway.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 530/540 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP322-ECP?",
        "a": "SKF NUP 322 ECP is a single-row caged cylindrical roller bearing with 110 mm bore, 240 mm OD and 50 mm width per ISO 15. SKF lists C 530 kN, C0 540 kN, Pu 61 kN, reference speed 3,000 r/min and limiting speed 3,400 r/min, mass about 10500 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP322-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP322-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP322",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×50 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ322-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×50 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU322-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 110×240×50 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP322-ECP",
      "SKF NUP 322 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP324-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 324 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 610,
    "static_load_kN": 620,
    "fatigue_load_limit_kN": 69.5,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 14000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "Ordering number SKF NUP 324 ECP resolves to a 120×260×55 mm single-row caged cylindrical roller bearing (dimension series 3 (medium-section ISO 15 envelope)); two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Selection arithmetic: C0/C ≈ 1.02 (620 against 610 kN), and the Pu figure 69.5 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,800 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 324, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 324 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 610/620 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP324-ECP?",
        "a": "SKF NUP 324 ECP is a single-row caged cylindrical roller bearing with 120 mm bore, 260 mm OD and 55 mm width per ISO 15. SKF lists C 610 kN, C0 620 kN, Pu 69.5 kN, reference speed 2,800 r/min and limiting speed 3,200 r/min, mass about 14000 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP324-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP324-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP324",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 120×260×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N324-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×55 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ324-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×55 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU324-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 120×260×55 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP324-ECP",
      "SKF NUP 324 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP326-ECP",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 326 ECP",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 720,
    "static_load_kN": 750,
    "fatigue_load_limit_kN": 81.5,
    "max_rpm": 3000,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3000,
    "weight_g": 19500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NUP326-ECP is the 130 mm bore entry in the NUP300 range: a 130×280×58 mm single-row caged cylindrical roller bearing with a glass-fibre reinforced polyamide (PA66) window-type cage, rated C 720 kN / C0 750 kN. Structurally, the NUP design has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. In arrangement terms it is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Speed planning for NUP326-ECP: the catalogue lists 2,400 r/min thermal reference speed and 3,000 r/min mechanical limiting speed. The mass entry 19500 g covers the complete catalogue execution. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C — the PA66 cage sets the ceiling.",
    "applications": [
      "mining hoist and winder shafts",
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "polymer cage softening above 120 °C",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 326, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 326 ECP and do not substitute rib styles without checking the shaft locating scheme.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 720/750 kN ratings are SKF catalogue 17000 (2018) values for the ECP execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP326-ECP?",
        "a": "SKF NUP 326 ECP is a single-row caged cylindrical roller bearing with 130 mm bore, 280 mm OD and 58 mm width per ISO 15. SKF lists C 720 kN, C0 750 kN, Pu 81.5 kN, reference speed 2,400 r/min and limiting speed 3,000 r/min, mass about 19500 g."
      },
      {
        "q": "What does the NUP designation and ECP suffix mean?",
        "a": "The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP326-ECP take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP326-ECP compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP326",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 130×280×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "N326-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×58 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NJ326-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×58 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU326-ECP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 130×280×58 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP326-ECP",
      "SKF NUP 326 ECP"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP328-ECM",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 328 ECM",
    "series": "NUP300-series",
    "type": "cylindrical_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 780,
    "static_load_kN": 830,
    "fatigue_load_limit_kN": 88,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 23500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, SKF NUP 328 ECM denotes a single-row caged cylindrical roller bearing on the ISO 15 140×300×62 mm envelope, dimension series 3 (medium-section ISO 15 envelope), with catalogue mass 23500 g. Reading the NUP prefix: two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring. This makes the execution a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECM: the E-design ECM execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 1.06 (830 against 780 kN), and the Pu figure 88 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 2,400 r/min thermal reference speed and 2,800 r/min mechanical limiting speed. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 140 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 328, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 328 ECM and do not substitute rib styles without checking the shaft locating scheme.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 62 mm-wide ring and concentrates load.",
      "Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.",
      "The 780/830 kN ratings are SKF catalogue 17000 (2018) values for the ECM execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP328-ECM?",
        "a": "SKF NUP 328 ECM is a single-row caged cylindrical roller bearing with 140 mm bore, 300 mm OD and 62 mm width per ISO 15. SKF lists C 780 kN, C0 830 kN, Pu 88 kN, reference speed 2,400 r/min and limiting speed 2,800 r/min, mass about 23500 g."
      },
      {
        "q": "What does the NUP designation and ECM suffix mean?",
        "a": "The ECM suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP328-ECM take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP328-ECM compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP328",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 140×300×62 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NJ328-ECJ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×62 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      },
      {
        "equiv_sku": "NU328-ECM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same ISO 15 envelope 140×300×62 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP328-ECM",
      "SKF NUP 328 ECM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP3984-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 3984 ECMA",
    "series": "NUP3900-series",
    "type": "cylindrical_roller",
    "d_mm": 420,
    "D_mm": 560,
    "B_mm": 106,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 1680,
    "static_load_kN": 3650,
    "fatigue_load_limit_kN": 310,
    "max_rpm": 1500,
    "reference_speed_rpm": 950,
    "limiting_speed_rpm": 1500,
    "weight_g": 79500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For a 420 mm shaft, SKF lists NUP3984-ECMA as single-row caged cylindrical roller: 560 mm OD, 106 mm wide, Pu 310 kN, the catalogue lists 950 r/min thermal reference speed and 1,500 r/min mechanical limiting speed. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Load-per-bore for the 420 mm seat is about 4.00 kN/mm, typical of dimension series 39 (compact OD); use C0 3650 kN for static checks such as crane hook blocks standing under load. Mounting: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. A 420 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.",
    "applications": [
      "offshore drawworks shafts",
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 39 (compact OD) envelope is shared with the N/NU/NJ/NUP executions of 3984, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 3984 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 560 mm raceway.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 560 mm raceway.",
      "The 1680/3650 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP3984-ECMA?",
        "a": "SKF NUP 3984 ECMA is a single-row caged cylindrical roller bearing with 420 mm bore, 560 mm OD and 106 mm width per ISO 15. SKF lists C 1680 kN, C0 3650 kN, Pu 310 kN, reference speed 950 r/min and limiting speed 1,500 r/min, mass about 79500 g."
      },
      {
        "q": "What does the NUP designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP3984-ECMA take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP3984-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP3984",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP3984-ECMA",
      "SKF NUP 3984 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NUP3992-ECMA",
    "brand": "SKF",
    "manufacturer_designation": "SKF NUP 3992 ECMA",
    "series": "NUP3900-series",
    "type": "cylindrical_roller",
    "d_mm": 460,
    "D_mm": 620,
    "B_mm": 118,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 2050,
    "static_load_kN": 4550,
    "fatigue_load_limit_kN": 375,
    "max_rpm": 1300,
    "reference_speed_rpm": 850,
    "limiting_speed_rpm": 1300,
    "weight_g": 112000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF NUP 3992 ECMA is a single-row caged cylindrical roller bearing sized 460×620×118 mm — a dimension series 39 (compact OD), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. Reading the order-string suffix ECMA: the E-design ECMA execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. Selection arithmetic: C0/C ≈ 2.22 (4550 against 2050 kN), and the Pu figure 375 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 850 r/min thermal reference speed and 1,300 r/min mechanical limiting speed. Assembly note: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. Heat steel rings inductively to max 120 °C.",
    "applications": [
      "large rolling-mill drive trains",
      "marine propulsion line shafts",
      "heavy turbogenerator rotor supports",
      "mining hoist and winder shafts"
    ],
    "failure_modes": [
      "inner-ring raceway spalling from overload or contamination in the line-contact hertz zone",
      "outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating",
      "cage pocket wear from roller skew at light load",
      "polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant",
      "roller-end scoring from inadequate oil flow in the roller-raceway contact",
      "edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit",
      "brinelling from static overload or impact during handling and mounting"
    ],
    "pitfalls": [
      "Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing",
      "The dimension series 39 (compact OD) envelope is shared with the N/NU/NJ/NUP executions of 3992, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 3992 ECMA and do not substitute rib styles without checking the shaft locating scheme.",
      "Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 620 mm raceway.",
      "Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 118 mm-wide ring and concentrates load.",
      "The 2050/4550 kN ratings are SKF catalogue 17000 (2018) values for the ECMA execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue data of NUP3992-ECMA?",
        "a": "SKF NUP 3992 ECMA is a single-row caged cylindrical roller bearing with 460 mm bore, 620 mm OD and 118 mm width per ISO 15. SKF lists C 2050 kN, C0 4550 kN, Pu 375 kN, reference speed 850 r/min and limiting speed 1,300 r/min, mass about 112000 g."
      },
      {
        "q": "What does the NUP designation and ECMA suffix mean?",
        "a": "The ECMA suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring."
      },
      {
        "q": "Can NUP3992-ECMA take axial load and locate the shaft?",
        "a": "Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance."
      },
      {
        "q": "How does NUP3992-ECMA compare with the other executions in the same envelope?",
        "a": "The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number."
      },
      {
        "q": "What limits the service life of this bearing most often?",
        "a": "Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NUP3992",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/roller-bearings/cylindrical-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NUP3992-ECMA",
      "SKF NUP 3992 ECMA"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K3X5X7-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 3x5x7 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 3,
    "D_mm": 5,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 1.51,
    "static_load_kN": 1.34,
    "fatigue_load_limit_kN": 0.134,
    "max_rpm": 45000,
    "reference_speed_rpm": 40000,
    "limiting_speed_rpm": 45000,
    "weight_g": 0.3,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 3x5x7 TN in the K series of needle roller and cage assemblies: needle rollers caged at 3×5×7 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 3×5×7 is a boundary plan, not an envelope: the assembly has no rings, so E 5 mm is the needle set diameter the housing bore must match, and the 3 mm journal must be ground and hardened. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 45,000 r/min limiting speed assumes a precision ground journal and bore. Speed planning separates the two ceilings: 40,000 r/min thermal reference and 45,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 3 mm seat. Mounting: grind the 3 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 5 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 3 mm the rolling elements are under two millimetres long — handle the K 3x5x7 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Reference and limiting speeds are different limits: the 40,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 3 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 1.51/1.34 kN ratings and 0.3 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a K 3x5x7 TN?",
        "a": "Slide the assembly over the ground 3 mm journal with a mounting sleeve, bore the housing to E 5 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 3x5x7 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 3x5x7 TN have?",
        "a": "A K 3x5x7 TN measures 3 mm bore/Fw × 5 mm outside diameter × 7 mm width (0.118 × 0.197 × 0.276 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 1.51 kN, static C0 1.34 kN, fatigue limit Pu 0.134 kN, limiting speed 45,000 r/min, reference speed 40,000 r/min, mass about 0.3 g."
      },
      {
        "q": "What does K 3x5x7 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 3 mm (shaft journal), E 5 mm (complement outside diameter, matched by the housing bore) and B 7 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K3X5X7",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K3X5X7-TN",
      "K 3x5x7 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K3X5X9-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 3x5x9 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 3,
    "D_mm": 5,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 1.68,
    "static_load_kN": 1.53,
    "fatigue_load_limit_kN": 0.153,
    "max_rpm": 45000,
    "reference_speed_rpm": 40000,
    "limiting_speed_rpm": 45000,
    "weight_g": 0.4,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 3x5x9 TN denotes a needle roller and cage assembly for a 3 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 9 mm width is all the radial room it needs. The designation numbers of K 3x5x9 TN state the three machine-seat dimensions — 3 mm journal, 5 mm bore-side complement diameter, 9 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Selection arithmetic: C 1.68 kN against C0 1.53 kN gives a C0/C ratio of 0.91, and the 0.153 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: grind the 3 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 5 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 3 mm the rolling elements are under two millimetres long — handle the K 3x5x9 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 1.68/1.53 kN ratings and 0.4 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the K 3x5x9 TN be mounted?",
        "a": "Slide the assembly over the ground 3 mm journal with a mounting sleeve, bore the housing to E 5 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 3x5x9 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 3 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 1.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 3x5x9 TN?",
        "a": "A K 3x5x9 TN measures 3 mm bore/Fw × 5 mm outside diameter × 9 mm width (0.118 × 0.197 × 0.354 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 1.68 kN, static C0 1.53 kN, fatigue limit Pu 0.153 kN, limiting speed 45,000 r/min, reference speed 40,000 r/min, mass about 0.4 g."
      },
      {
        "q": "How is the K 3x5x9 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 3 mm (shaft journal), E 5 mm (complement outside diameter, matched by the housing bore) and B 9 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K3X5X9",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K3X5X9-TN",
      "K 3x5x9 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K4X7X7-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 4x7x7 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 4,
    "D_mm": 7,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 1.72,
    "static_load_kN": 1.32,
    "fatigue_load_limit_kN": 0.137,
    "max_rpm": 43000,
    "reference_speed_rpm": 36000,
    "limiting_speed_rpm": 43000,
    "weight_g": 0.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "The K assembly K 4x7x7 TN is the lowest-radial-section rolling bearing available for a 4 mm shaft: only the 7 mm wide cage-and-roller set sits between journal and bore, giving extreme compactness where even a drawn cup is too heavy a section. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 4 (shaft journal), E 7 (assembly outside diameter) and B 7 (width) in millimetres — the machine parts complete the bearing. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Speed planning separates the two ceilings: 36,000 r/min thermal reference and 43,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 4 mm seat. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 4 mm the rolling elements are under two millimetres long — handle the K 4x7x7 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 4x7x7 TN shares its 4×7×7 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 1.72/1.32 kN ratings and 0.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a K 4x7x7 TN?",
        "a": "Slide the assembly over the ground 4 mm journal with a mounting sleeve, bore the housing to E 7 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 4x7x7 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 4x7x7 TN have?",
        "a": "A K 4x7x7 TN measures 4 mm bore/Fw × 7 mm outside diameter × 7 mm width (0.157 × 0.276 × 0.276 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 1.72 kN, static C0 1.32 kN, fatigue limit Pu 0.137 kN, limiting speed 43,000 r/min, reference speed 36,000 r/min, mass about 0.5 g."
      },
      {
        "q": "What does K 4x7x7 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 4 mm (shaft journal), E 7 mm (complement outside diameter, matched by the housing bore) and B 7 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K4X7X7",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K4X7X7-TN",
      "K 4x7x7 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K4X7X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 4x7x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 4,
    "D_mm": 7,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.29,
    "static_load_kN": 1.9,
    "fatigue_load_limit_kN": 0.204,
    "max_rpm": 43000,
    "reference_speed_rpm": 36000,
    "limiting_speed_rpm": 43000,
    "weight_g": 0.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 4x7x10 TN is a caged needle roller set, not a complete bearing: paired with a 58–64 HRC ground journal of 4 mm and a housing bore of 7 mm, it forms a full rolling bearing with the smallest possible radial space demand. In the K code K 4x7x10 TN, Fw×E×B reads directly as journal 4 mm, complement diameter 7 mm and cage width 10 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Catalogue mass 0.7 g at 4×7×10 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 4 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 7 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 4 mm the rolling elements are under two millimetres long — handle the K 4x7x10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Hardness is load capacity: in families without an inner ring the 4 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 2.29/1.9 kN ratings are SKF catalogue values for this exact execution (K 4x7x10 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 2.29/1.9 kN ratings and 0.7 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a K 4x7x10 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 4 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 1.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 4x7x10 TN?",
        "a": "A K 4x7x10 TN measures 4 mm bore/Fw × 7 mm outside diameter × 10 mm width (0.157 × 0.276 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.29 kN, static C0 1.9 kN, fatigue limit Pu 0.204 kN, limiting speed 43,000 r/min, reference speed 36,000 r/min, mass about 0.7 g."
      },
      {
        "q": "How is the K 4x7x10 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 4 mm (shaft journal), E 7 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 4x7x10 TN run on an unhardened shaft?",
        "a": "No. In this execution the 4 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K4X7X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K4X7X10-TN",
      "K 4x7x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K5X8X8-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 5x8x8 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 8,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.29,
    "static_load_kN": 2,
    "fatigue_load_limit_kN": 0.212,
    "max_rpm": 40000,
    "reference_speed_rpm": 36000,
    "limiting_speed_rpm": 40000,
    "weight_g": 0.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 5x8x8 TN in the K series of needle roller and cage assemblies: needle rollers caged at 5×8×8 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. The designation numbers of K 5x8x8 TN state the three machine-seat dimensions — 5 mm journal, 8 mm bore-side complement diameter, 8 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. The 0.7 g catalogue mass and 1.5 mm radial section ((8−5)/2) frame a rating of about 0.46 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: grind the 5 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 8 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the K 5x8x8 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Hardness is load capacity: in families without an inner ring the 5 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 2.29/2 kN ratings are SKF catalogue values for this exact execution (K 5x8x8 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 2.29/2 kN ratings and 0.7 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the K 5x8x8 TN?",
        "a": "A K 5x8x8 TN measures 5 mm bore/Fw × 8 mm outside diameter × 8 mm width (0.197 × 0.315 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.29 kN, static C0 2 kN, fatigue limit Pu 0.212 kN, limiting speed 40,000 r/min, reference speed 36,000 r/min, mass about 0.7 g."
      },
      {
        "q": "How is the K 5x8x8 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 5 mm (shaft journal), E 8 mm (complement outside diameter, matched by the housing bore) and B 8 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 5x8x8 TN run on an unhardened shaft?",
        "a": "No. In this execution the 5 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 5x8x8 TN be mounted?",
        "a": "Slide the assembly over the ground 5 mm journal with a mounting sleeve, bore the housing to E 8 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K5X8X8",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K5X8X8-TN",
      "K 5x8x8 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K5X8X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 5x8x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 8,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.92,
    "static_load_kN": 2.7,
    "fatigue_load_limit_kN": 0.29,
    "max_rpm": 40000,
    "reference_speed_rpm": 36000,
    "limiting_speed_rpm": 40000,
    "weight_g": 0.9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 5x8x10 TN denotes a needle roller and cage assembly for a 5 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 10 mm width is all the radial room it needs. K 5×8×10 is a boundary plan, not an envelope: the assembly has no rings, so E 8 mm is the needle set diameter the housing bore must match, and the 5 mm journal must be ground and hardened. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 10 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the K 5x8x10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 2.92/2.7 kN ratings are SKF catalogue values for this exact execution (K 5x8x10 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 2.92/2.7 kN ratings and 0.9 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 5x8x10 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 5x8x10 TN have?",
        "a": "A K 5x8x10 TN measures 5 mm bore/Fw × 8 mm outside diameter × 10 mm width (0.197 × 0.315 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.92 kN, static C0 2.7 kN, fatigue limit Pu 0.29 kN, limiting speed 40,000 r/min, reference speed 36,000 r/min, mass about 0.9 g."
      },
      {
        "q": "What does K 5x8x10 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 5 mm (shaft journal), E 8 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 5x8x10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 5 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K5X8X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K5X8X10-TN",
      "K 5x8x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K6X9X8-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 6x9x8 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 9,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.55,
    "static_load_kN": 2.36,
    "fatigue_load_limit_kN": 0.25,
    "max_rpm": 38000,
    "reference_speed_rpm": 34000,
    "limiting_speed_rpm": 38000,
    "weight_g": 0.8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 6x9x8 TN: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 6 × E 9 × B 8 mm. In the K code K 6x9x8 TN, Fw×E×B reads directly as journal 6 mm, complement diameter 9 mm and cage width 8 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 8 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the K 6x9x8 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 2.55/2.36 kN ratings and 0.8 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 6x9x8 TN run on an unhardened shaft?",
        "a": "No. In this execution the 6 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 6x9x8 TN be mounted?",
        "a": "Slide the assembly over the ground 6 mm journal with a mounting sleeve, bore the housing to E 9 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 6x9x8 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 6 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 1.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 6x9x8 TN?",
        "a": "A K 6x9x8 TN measures 6 mm bore/Fw × 9 mm outside diameter × 8 mm width (0.236 × 0.354 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.55 kN, static C0 2.36 kN, fatigue limit Pu 0.25 kN, limiting speed 38,000 r/min, reference speed 34,000 r/min, mass about 0.8 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K6X9X8",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K6X9X8-TN",
      "K 6x9x8 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K6X9X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 6x9x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 9,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.3,
    "static_load_kN": 3.2,
    "fatigue_load_limit_kN": 0.345,
    "max_rpm": 38000,
    "reference_speed_rpm": 34000,
    "limiting_speed_rpm": 38000,
    "weight_g": 1.1,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 6x9x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 6×9×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 6×9×10 is a boundary plan, not an envelope: the assembly has no rings, so E 9 mm is the needle set diameter the housing bore must match, and the 6 mm journal must be ground and hardened. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the K 6x9x10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 6x9x10 TN shares its 6×9×10 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 3.3/3.2 kN ratings and 1.1 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 6x9x10 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 6x9x10 TN have?",
        "a": "A K 6x9x10 TN measures 6 mm bore/Fw × 9 mm outside diameter × 10 mm width (0.236 × 0.354 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.3 kN, static C0 3.2 kN, fatigue limit Pu 0.345 kN, limiting speed 38,000 r/min, reference speed 34,000 r/min, mass about 1.1 g."
      },
      {
        "q": "What does K 6x9x10 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 6 mm (shaft journal), E 9 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 6x9x10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 6 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K6X9X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K6X9X10-TN",
      "K 6x9x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K7X10X8-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 7x10x8 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 10,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.81,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.29,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 0.9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 7x10x8 TN denotes a needle roller and cage assembly for a 7 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 8 mm width is all the radial room it needs. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 7 (shaft journal), E 10 (assembly outside diameter) and B 8 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 36,000 r/min limiting speed assumes a precision ground journal and bore. Selection arithmetic: C 2.81 kN against C0 2.75 kN gives a C0/C ratio of 0.98, and the 0.29 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: grind the 7 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 10 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the K 7x10x8 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 2.81/2.75 kN ratings are SKF catalogue values for this exact execution (K 7x10x8 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 2.81/2.75 kN ratings and 0.9 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 7x10x8 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 7 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 7x10x8 TN?",
        "a": "Slide the assembly over the ground 7 mm journal with a mounting sleeve, bore the housing to E 10 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 7x10x8 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 7x10x8 TN have?",
        "a": "A K 7x10x8 TN measures 7 mm bore/Fw × 10 mm outside diameter × 8 mm width (0.276 × 0.394 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.81 kN, static C0 2.75 kN, fatigue limit Pu 0.29 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 0.9 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K7X10X8",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K7X10X8-TN",
      "K 7x10x8 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K7X10X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 7x10x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 10,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.58,
    "static_load_kN": 3.75,
    "fatigue_load_limit_kN": 0.415,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 1,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 7x10x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 7×10×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 7×10×10 is a boundary plan, not an envelope: the assembly has no rings, so E 10 mm is the needle set diameter the housing bore must match, and the 7 mm journal must be ground and hardened. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 36,000 r/min limiting speed assumes a precision ground journal and bore. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: grind the 7 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 10 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the K 7x10x10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Reference and limiting speeds are different limits: the 32,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 7 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 3.58/3.75 kN ratings and 1 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 7x10x10 TN have?",
        "a": "A K 7x10x10 TN measures 7 mm bore/Fw × 10 mm outside diameter × 10 mm width (0.276 × 0.394 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.58 kN, static C0 3.75 kN, fatigue limit Pu 0.415 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 1 g."
      },
      {
        "q": "What does K 7x10x10 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 7 mm (shaft journal), E 10 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 7x10x10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 7 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 7x10x10 TN?",
        "a": "Slide the assembly over the ground 7 mm journal with a mounting sleeve, bore the housing to E 10 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K7X10X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K7X10X10-TN",
      "K 7x10x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K8X11X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 8x11x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 11,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.8,
    "static_load_kN": 4.25,
    "fatigue_load_limit_kN": 0.465,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 1.2,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 8x11x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 8×11×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. The designation numbers of K 8x11x10 TN state the three machine-seat dimensions — 8 mm journal, 11 mm bore-side complement diameter, 10 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. For life calculation, the 3.8/4.25 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 10 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the K 8x11x10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: K 8x11x10 TN shares its 8×11×10 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 32,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 3.8/4.25 kN ratings and 1.2 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the K 8x11x10 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 8 mm (shaft journal), E 11 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 8x11x10 TN run on an unhardened shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 8x11x10 TN be mounted?",
        "a": "Slide the assembly over the ground 8 mm journal with a mounting sleeve, bore the housing to E 11 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 8x11x10 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 8 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 1.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K8X11X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K8X11X10-TN",
      "K 8x11x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K8X11X13-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 8x11x13 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 11,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.01,
    "static_load_kN": 5.85,
    "fatigue_load_limit_kN": 0.67,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 1.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 8x11x13 TN denotes a needle roller and cage assembly for a 8 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 13 mm width is all the radial room it needs. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 8 (shaft journal), E 11 (assembly outside diameter) and B 13 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Speed planning separates the two ceilings: 32,000 r/min thermal reference and 36,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 8 mm seat. Mounting: grind the 8 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 11 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the K 8x11x13 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 8x11x13 TN shares its 8×11×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 5.01/5.85 kN ratings and 1.7 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 8x11x13 TN have?",
        "a": "A K 8x11x13 TN measures 8 mm bore/Fw × 11 mm outside diameter × 13 mm width (0.315 × 0.433 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.01 kN, static C0 5.85 kN, fatigue limit Pu 0.67 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 1.7 g."
      },
      {
        "q": "What does K 8x11x13 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 8 mm (shaft journal), E 11 mm (complement outside diameter, matched by the housing bore) and B 13 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 8x11x13 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 8x11x13 TN?",
        "a": "Slide the assembly over the ground 8 mm journal with a mounting sleeve, bore the housing to E 11 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K8X11X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K8X11X13-TN",
      "K 8x11x13 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K8X12X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 8x12x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 12,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.84,
    "static_load_kN": 4.75,
    "fatigue_load_limit_kN": 0.54,
    "max_rpm": 34000,
    "reference_speed_rpm": 30000,
    "limiting_speed_rpm": 34000,
    "weight_g": 2,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 8x12x10 TN appears as a needle roller and cage assembly with complement diameter E 12 mm and width 10 mm — a self-contained roller set that turns a 8 mm shaft and its housing into a complete bearing. The designation numbers of K 8x12x10 TN state the three machine-seat dimensions — 8 mm journal, 12 mm bore-side complement diameter, 10 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 10 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the K 8x12x10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: K 8x12x10 TN shares its 8×12×10 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 30,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 4.84/4.75 kN ratings and 2 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the K 8x12x10 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 8 mm (shaft journal), E 12 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 8x12x10 TN run on an unhardened shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 8x12x10 TN be mounted?",
        "a": "Slide the assembly over the ground 8 mm journal with a mounting sleeve, bore the housing to E 12 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 8x12x10 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 8 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K8X12X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K8X12X10-TN",
      "K 8x12x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K9X12X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 9x12x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 12,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.4,
    "static_load_kN": 5.2,
    "fatigue_load_limit_kN": 0.57,
    "max_rpm": 34000,
    "reference_speed_rpm": 30000,
    "limiting_speed_rpm": 34000,
    "weight_g": 1.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 9x12x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 9×12×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 9 (shaft journal), E 12 (assembly outside diameter) and B 10 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. The 1.5 g catalogue mass and 1.5 mm radial section ((12−9)/2) frame a rating of about 0.49 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 12 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 9x12x10 TN shares its 9×12×10 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 4.4/5.2 kN ratings and 1.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 9x12x10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 9 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 9x12x10 TN?",
        "a": "Slide the assembly over the ground 9 mm journal with a mounting sleeve, bore the housing to E 12 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 9x12x10 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 9x12x10 TN have?",
        "a": "A K 9x12x10 TN measures 9 mm bore/Fw × 12 mm outside diameter × 10 mm width (0.354 × 0.472 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.4 kN, static C0 5.2 kN, fatigue limit Pu 0.57 kN, limiting speed 34,000 r/min, reference speed 30,000 r/min, mass about 1.5 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K9X12X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K9X12X10-TN",
      "K 9x12x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K10X13X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 10x13x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 13,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.57,
    "static_load_kN": 5.7,
    "fatigue_load_limit_kN": 0.63,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 1.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 10x13x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 10×13×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 10 (shaft journal), E 13 (assembly outside diameter) and B 10 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 32,000 r/min limiting speed assumes a precision ground journal and bore. Catalogue mass 1.6 g at 10×13×10 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 10 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 13 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 13 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 4.57/5.7 kN ratings are SKF catalogue values for this exact execution (K 10x13x10 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 4.57/5.7 kN ratings and 1.6 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 10x13x10 TN have?",
        "a": "A K 10x13x10 TN measures 10 mm bore/Fw × 13 mm outside diameter × 10 mm width (0.394 × 0.512 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.57 kN, static C0 5.7 kN, fatigue limit Pu 0.63 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 1.6 g."
      },
      {
        "q": "What does K 10x13x10 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 10 mm (shaft journal), E 13 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 10x13x10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 10x13x10 TN?",
        "a": "Slide the assembly over the ground 10 mm journal with a mounting sleeve, bore the housing to E 13 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K10X13X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K10X13X10-TN",
      "K 10x13x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K10X13X13-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 10x13x13 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 13,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.94,
    "static_load_kN": 8,
    "fatigue_load_limit_kN": 0.9,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 2.3,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 10x13x13 TN denotes a needle roller and cage assembly for a 10 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 13 mm width is all the radial room it needs. K 10×13×13 is a boundary plan, not an envelope: the assembly has no rings, so E 13 mm is the needle set diameter the housing bore must match, and the 10 mm journal must be ground and hardened. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 32,000 r/min limiting speed assumes a precision ground journal and bore. For life calculation, the 5.94/8 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 13 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 13 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 28,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 10 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 5.94/8 kN ratings and 2.3 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 10x13x13 TN have?",
        "a": "A K 10x13x13 TN measures 10 mm bore/Fw × 13 mm outside diameter × 13 mm width (0.394 × 0.512 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.94 kN, static C0 8 kN, fatigue limit Pu 0.9 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 2.3 g."
      },
      {
        "q": "What does K 10x13x13 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 10 mm (shaft journal), E 13 mm (complement outside diameter, matched by the housing bore) and B 13 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 10x13x13 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 10x13x13 TN?",
        "a": "Slide the assembly over the ground 10 mm journal with a mounting sleeve, bore the housing to E 13 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K10X13X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K10X13X13-TN",
      "K 10x13x13 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K10X14X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 10x14x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 14,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.61,
    "static_load_kN": 6.1,
    "fatigue_load_limit_kN": 0.695,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 2.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 10x14x10 TN appears as a needle roller and cage assembly with complement diameter E 14 mm and width 10 mm — a self-contained roller set that turns a 10 mm shaft and its housing into a complete bearing. In the K code K 10x14x10 TN, Fw×E×B reads directly as journal 10 mm, complement diameter 14 mm and cage width 10 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Catalogue mass 2.5 g at 10×14×10 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 10 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 14 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 14 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 10 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 5.61/6.1 kN ratings are SKF catalogue values for this exact execution (K 10x14x10 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 5.61/6.1 kN ratings and 2.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the K 10x14x10 TN?",
        "a": "A K 10x14x10 TN measures 10 mm bore/Fw × 14 mm outside diameter × 10 mm width (0.394 × 0.551 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.61 kN, static C0 6.1 kN, fatigue limit Pu 0.695 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 2.5 g."
      },
      {
        "q": "How is the K 10x14x10 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 10 mm (shaft journal), E 14 mm (complement outside diameter, matched by the housing bore) and B 10 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 10x14x10 TN run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 10x14x10 TN be mounted?",
        "a": "Slide the assembly over the ground 10 mm journal with a mounting sleeve, bore the housing to E 14 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K10X14X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K10X14X10-TN",
      "K 10x14x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K10X14X13-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 10x14x13 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 14,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 7.21,
    "static_load_kN": 8.5,
    "fatigue_load_limit_kN": 0.98,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 4.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 10x14x13 TN denotes a needle roller and cage assembly for a 10 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 13 mm width is all the radial room it needs. The designation numbers of K 10x14x13 TN state the three machine-seat dimensions — 10 mm journal, 14 mm bore-side complement diameter, 13 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 32,000 r/min limiting speed assumes a precision ground journal and bore. For life calculation, the 7.21/8.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 14 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: K 10x14x13 TN shares its 10×14×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 28,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 7.21/8.5 kN ratings and 4.6 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the K 10x14x13 TN?",
        "a": "A K 10x14x13 TN measures 10 mm bore/Fw × 14 mm outside diameter × 13 mm width (0.394 × 0.551 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.21 kN, static C0 8.5 kN, fatigue limit Pu 0.98 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 4.6 g."
      },
      {
        "q": "How is the K 10x14x13 TN designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 10 mm (shaft journal), E 14 mm (complement outside diameter, matched by the housing bore) and B 13 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 10x14x13 TN run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 10x14x13 TN be mounted?",
        "a": "Slide the assembly over the ground 10 mm journal with a mounting sleeve, bore the housing to E 14 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K10X14X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K10X14X13-TN",
      "K 10x14x13 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K10X16X12-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 10x16x12 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 16,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 7.65,
    "static_load_kN": 7.2,
    "fatigue_load_limit_kN": 0.85,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 5.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 10x16x12 TN appears as a needle roller and cage assembly with complement diameter E 16 mm and width 12 mm — a self-contained roller set that turns a 10 mm shaft and its housing into a complete bearing. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 10 (shaft journal), E 16 (assembly outside diameter) and B 12 (width) in millimetres — the machine parts complete the bearing. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 12 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 16 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 7.65/7.2 kN ratings are SKF catalogue values for this exact execution (K 10x16x12 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 7.65/7.2 kN ratings and 5.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 10x16x12 TN have?",
        "a": "A K 10x16x12 TN measures 10 mm bore/Fw × 16 mm outside diameter × 12 mm width (0.394 × 0.63 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.65 kN, static C0 7.2 kN, fatigue limit Pu 0.85 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 5.5 g."
      },
      {
        "q": "What does K 10x16x12 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 10 mm (shaft journal), E 16 mm (complement outside diameter, matched by the housing bore) and B 12 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 10x16x12 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 10x16x12 TN?",
        "a": "Slide the assembly over the ground 10 mm journal with a mounting sleeve, bore the housing to E 16 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K10X16X12",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K10X16X12-TN",
      "K 10x16x12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K12X15X10-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 12x15x10 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 15,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.73,
    "static_load_kN": 6.2,
    "fatigue_load_limit_kN": 0.695,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 2.9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 12x15x10 TN in the K series of needle roller and cage assemblies: needle rollers caged at 12×15×10 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 12×15×10 is a boundary plan, not an envelope: the assembly has no rings, so E 15 mm is the needle set diameter the housing bore must match, and the 12 mm journal must be ground and hardened. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. For life calculation, the 4.73/6.2 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 15 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 26,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 4.73/6.2 kN ratings and 2.9 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 12x15x10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 12x15x10 TN?",
        "a": "Slide the assembly over the ground 12 mm journal with a mounting sleeve, bore the housing to E 15 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 12x15x10 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 12x15x10 TN have?",
        "a": "A K 12x15x10 TN measures 12 mm bore/Fw × 15 mm outside diameter × 10 mm width (0.472 × 0.591 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.73 kN, static C0 6.2 kN, fatigue limit Pu 0.695 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 2.9 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K12X15X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K12X15X10-TN",
      "K 12x15x10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K12X15X13-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 12x15x13 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 15,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 6.16,
    "static_load_kN": 8.65,
    "fatigue_load_limit_kN": 0.98,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 2.3,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 12x15x13 TN denotes a needle roller and cage assembly for a 12 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 13 mm width is all the radial room it needs. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 12 (shaft journal), E 15 (assembly outside diameter) and B 13 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Speed planning separates the two ceilings: 26,000 r/min thermal reference and 30,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 12 mm seat. Mounting: grind the 12 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 15 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 15 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 12x15x13 TN shares its 12×15×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 6.16/8.65 kN ratings and 2.3 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 12x15x13 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 12x15x13 TN?",
        "a": "Slide the assembly over the ground 12 mm journal with a mounting sleeve, bore the housing to E 15 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 12x15x13 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 12x15x13 TN have?",
        "a": "A K 12x15x13 TN measures 12 mm bore/Fw × 15 mm outside diameter × 13 mm width (0.472 × 0.591 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 6.16 kN, static C0 8.65 kN, fatigue limit Pu 0.98 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 2.3 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K12X15X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K12X15X13-TN",
      "K 12x15x13 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K12X16X13-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 12x16x13 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 16,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 7.65,
    "static_load_kN": 9.5,
    "fatigue_load_limit_kN": 1.1,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 3.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 12x16x13 TN denotes a needle roller and cage assembly for a 12 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 13 mm width is all the radial room it needs. In the K code K 12x16x13 TN, Fw×E×B reads directly as journal 12 mm, complement diameter 16 mm and cage width 13 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Speed planning separates the two ceilings: 26,000 r/min thermal reference and 30,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 12 mm seat. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 13 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 16 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 7.65/9.5 kN ratings and 3.6 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 12x16x13 TN run on an unhardened shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 12x16x13 TN be mounted?",
        "a": "Slide the assembly over the ground 12 mm journal with a mounting sleeve, bore the housing to E 16 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 12x16x13 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 12 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 12x16x13 TN?",
        "a": "A K 12x16x13 TN measures 12 mm bore/Fw × 16 mm outside diameter × 13 mm width (0.472 × 0.63 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.65 kN, static C0 9.5 kN, fatigue limit Pu 1.1 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 3.6 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K12X16X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K12X16X13-TN",
      "K 12x16x13 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K12X17X13-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 12x17x13 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 17,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 1.22,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 4.9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 12x17x13 TN in the K series of needle roller and cage assemblies: needle rollers caged at 12×17×13 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 12x17x13 TN, Fw×E×B reads directly as journal 12 mm, complement diameter 17 mm and cage width 13 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. The 4.9 g catalogue mass and 2.5 mm radial section ((17−12)/2) frame a rating of about 0.76 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 13 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 17 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 9.13/10.4 kN ratings and 4.9 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 12x17x13 TN run on an unhardened shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 12x17x13 TN be mounted?",
        "a": "Slide the assembly over the ground 12 mm journal with a mounting sleeve, bore the housing to E 17 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 12x17x13 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 12 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 12x17x13 TN?",
        "a": "A K 12x17x13 TN measures 12 mm bore/Fw × 17 mm outside diameter × 13 mm width (0.472 × 0.669 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 10.4 kN, fatigue limit Pu 1.22 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 4.9 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K12X17X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K12X17X13-TN",
      "K 12x17x13 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K12X18X12-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 12x18x12 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 18,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 9.52,
    "static_load_kN": 10,
    "fatigue_load_limit_kN": 1.18,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 12x18x12 TN appears as a needle roller and cage assembly with complement diameter E 18 mm and width 12 mm — a self-contained roller set that turns a 12 mm shaft and its housing into a complete bearing. K 12×18×12 is a boundary plan, not an envelope: the assembly has no rings, so E 18 mm is the needle set diameter the housing bore must match, and the 12 mm journal must be ground and hardened. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. The 6 g catalogue mass and 3.0 mm radial section ((18−12)/2) frame a rating of about 0.79 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: grind the 12 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 18 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 26,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 9.52/10 kN ratings and 6 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 12x18x12 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 12x18x12 TN?",
        "a": "Slide the assembly over the ground 12 mm journal with a mounting sleeve, bore the housing to E 18 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 12x18x12 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 12x18x12 TN have?",
        "a": "A K 12x18x12 TN measures 12 mm bore/Fw × 18 mm outside diameter × 12 mm width (0.472 × 0.709 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.52 kN, static C0 10 kN, fatigue limit Pu 1.18 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 6 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K12X18X12",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K12X18X12-TN",
      "K 12x18x12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K14X18X10",
    "brand": "SKF",
    "manufacturer_designation": "K 14x18x10",
    "series": "K-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 18,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.93,
    "static_load_kN": 8.65,
    "fatigue_load_limit_kN": 1,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 4,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 14x18x10 denotes a needle roller and cage assembly for a 14 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 10 mm width is all the radial room it needs. The designation numbers of K 14x18x10 state the three machine-seat dimensions — 14 mm journal, 18 mm bore-side complement diameter, 10 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 6.93/8.65 kN ratings and 4 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 14x18x10 run on an unhardened shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 14x18x10 be mounted?",
        "a": "Slide the assembly over the ground 14 mm journal with a mounting sleeve, bore the housing to E 18 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 14x18x10?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 14 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 14x18x10?",
        "a": "A K 14x18x10 measures 14 mm bore/Fw × 18 mm outside diameter × 10 mm width (0.551 × 0.709 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 6.93 kN, static C0 8.65 kN, fatigue limit Pu 1 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 4 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K14X18X10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K14X18X10",
      "K 14x18x10"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K14X18X13",
    "brand": "SKF",
    "manufacturer_designation": "K 14x18x13",
    "series": "K-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 18,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.92,
    "static_load_kN": 10.2,
    "fatigue_load_limit_kN": 1.18,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 6.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "The K assembly K 14x18x13 is the lowest-radial-section rolling bearing available for a 14 mm shaft: only the 13 mm wide cage-and-roller set sits between journal and bore, giving extreme compactness where even a drawn cup is too heavy a section. K 14×18×13 is a boundary plan, not an envelope: the assembly has no rings, so E 18 mm is the needle set diameter the housing bore must match, and the 14 mm journal must be ground and hardened. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 24,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 14 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 7.92/10.2 kN ratings and 6.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 14x18x13 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 14x18x13 have?",
        "a": "A K 14x18x13 measures 14 mm bore/Fw × 18 mm outside diameter × 13 mm width (0.551 × 0.709 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.92 kN, static C0 10.2 kN, fatigue limit Pu 1.18 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 6.5 g."
      },
      {
        "q": "What does K 14x18x13 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 14 mm (shaft journal), E 18 mm (complement outside diameter, matched by the housing bore) and B 13 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 14x18x13 need a hardened and ground shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K14X18X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K14X18X13",
      "K 14x18x13"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K14X18X15-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 14x18x15 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 18,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12.5,
    "fatigue_load_limit_kN": 1.46,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 14x18x15 TN denotes a needle roller and cage assembly for a 14 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 15 mm width is all the radial room it needs. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 14 (shaft journal), E 18 (assembly outside diameter) and B 15 (width) in millimetres — the machine parts complete the bearing. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. For life calculation, the 9.13/12.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: grind the 14 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 18 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 14x18x15 TN shares its 14×18×15 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 9.13/12.5 kN ratings and 5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a K 14x18x15 TN?",
        "a": "Slide the assembly over the ground 14 mm journal with a mounting sleeve, bore the housing to E 18 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 14x18x15 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 14x18x15 TN have?",
        "a": "A K 14x18x15 TN measures 14 mm bore/Fw × 18 mm outside diameter × 15 mm width (0.551 × 0.709 × 0.591 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12.5 kN, fatigue limit Pu 1.46 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 5 g."
      },
      {
        "q": "What does K 14x18x15 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 14 mm (shaft journal), E 18 mm (complement outside diameter, matched by the housing bore) and B 15 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K14X18X15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K14X18X15-TN",
      "K 14x18x15 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K14X18X17",
    "brand": "SKF",
    "manufacturer_designation": "K 14x18x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 18,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 14.6,
    "fatigue_load_limit_kN": 1.7,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 14x18x17 denotes a needle roller and cage assembly for a 14 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 17 mm width is all the radial room it needs. K 14×18×17 is a boundary plan, not an envelope: the assembly has no rings, so E 18 mm is the needle set diameter the housing bore must match, and the 14 mm journal must be ground and hardened. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 10.5/14.6 kN ratings are SKF catalogue values for this exact execution (K 14x18x17); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 10.5/14.6 kN ratings and 8 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 14x18x17 have?",
        "a": "A K 14x18x17 measures 14 mm bore/Fw × 18 mm outside diameter × 17 mm width (0.551 × 0.709 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 10.5 kN, static C0 14.6 kN, fatigue limit Pu 1.7 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 8 g."
      },
      {
        "q": "What does K 14x18x17 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 14 mm (shaft journal), E 18 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 14x18x17 need a hardened and ground shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 14x18x17?",
        "a": "Slide the assembly over the ground 14 mm journal with a mounting sleeve, bore the housing to E 18 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K14X18X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K14X18X17",
      "K 14x18x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K15X19X13",
    "brand": "SKF",
    "manufacturer_designation": "K 15x19x13",
    "series": "K-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 19,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.25,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 1.29,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 15x19x13 is a caged needle roller set, not a complete bearing: paired with a 58–64 HRC ground journal of 15 mm and a housing bore of 19 mm, it forms a full rolling bearing with the smallest possible radial space demand. The designation numbers of K 15x19x13 state the three machine-seat dimensions — 15 mm journal, 19 mm bore-side complement diameter, 13 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: grind the 15 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 19 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 8.25/11.2 kN ratings are SKF catalogue values for this exact execution (K 15x19x13); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 8.25/11.2 kN ratings and 7 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a K 15x19x13?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 15x19x13?",
        "a": "A K 15x19x13 measures 15 mm bore/Fw × 19 mm outside diameter × 13 mm width (0.591 × 0.748 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.25 kN, static C0 11.2 kN, fatigue limit Pu 1.29 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 7 g."
      },
      {
        "q": "How is the K 15x19x13 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 15 mm (shaft journal), E 19 mm (complement outside diameter, matched by the housing bore) and B 13 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 15x19x13 run on an unhardened shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K15X19X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K15X19X13",
      "K 15x19x13"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K15X19X17",
    "brand": "SKF",
    "manufacturer_designation": "K 15x19x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 19,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.8,
    "static_load_kN": 15.6,
    "fatigue_load_limit_kN": 1.86,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 9.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 15x19x17 in the K series of needle roller and cage assemblies: needle rollers caged at 15×19×17 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. The designation numbers of K 15x19x17 state the three machine-seat dimensions — 15 mm journal, 19 mm bore-side complement diameter, 17 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: grind the 15 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 19 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 10.8/15.6 kN ratings and 9.5 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the K 15x19x17?",
        "a": "A K 15x19x17 measures 15 mm bore/Fw × 19 mm outside diameter × 17 mm width (0.591 × 0.748 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 10.8 kN, static C0 15.6 kN, fatigue limit Pu 1.86 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 9.5 g."
      },
      {
        "q": "How is the K 15x19x17 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 15 mm (shaft journal), E 19 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 15x19x17 run on an unhardened shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 15x19x17 be mounted?",
        "a": "Slide the assembly over the ground 15 mm journal with a mounting sleeve, bore the housing to E 19 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K15X19X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K15X19X17",
      "K 15x19x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K15X21X15",
    "brand": "SKF",
    "manufacturer_designation": "K 15x21x15",
    "series": "K-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 21,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.8,
    "static_load_kN": 16.3,
    "fatigue_load_limit_kN": 2,
    "max_rpm": 26000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 26000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 15x21x15 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 15 mm hardened shaft journal and the 21 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 15 (shaft journal), E 21 (assembly outside diameter) and B 15 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 26,000 r/min limiting speed assumes a precision ground journal and bore. Speed planning separates the two ceilings: 24,000 r/min thermal reference and 26,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 15 mm seat. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 15x21x15 shares its 15×21×15 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 13.8/16.3 kN ratings and 11 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 15x21x15 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 15x21x15 have?",
        "a": "A K 15x21x15 measures 15 mm bore/Fw × 21 mm outside diameter × 15 mm width (0.591 × 0.827 × 0.591 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.8 kN, static C0 16.3 kN, fatigue limit Pu 2 kN, limiting speed 26,000 r/min, reference speed 24,000 r/min, mass about 11 g."
      },
      {
        "q": "What does K 15x21x15 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 15 mm (shaft journal), E 21 mm (complement outside diameter, matched by the housing bore) and B 15 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 15x21x15 need a hardened and ground shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K15X21X15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K15X21X15",
      "K 15x21x15"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K15X21X21",
    "brand": "SKF",
    "manufacturer_designation": "K 15x21x21",
    "series": "K-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 21,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 18.7,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 3,
    "max_rpm": 26000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 26000,
    "weight_g": 17,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 15x21x21 in the K series of needle roller and cage assemblies: needle rollers caged at 15×21×21 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 15x21x21, Fw×E×B reads directly as journal 15 mm, complement diameter 21 mm and cage width 21 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 26,000 r/min limiting speed assumes a precision ground journal and bore. Speed planning separates the two ceilings: 24,000 r/min thermal reference and 26,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 15 mm seat. Mounting: grind the 15 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 21 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 18.7/24.5 kN ratings and 17 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 616); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the K 15x21x21?",
        "a": "A K 15x21x21 measures 15 mm bore/Fw × 21 mm outside diameter × 21 mm width (0.591 × 0.827 × 0.827 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 18.7 kN, static C0 24.5 kN, fatigue limit Pu 3 kN, limiting speed 26,000 r/min, reference speed 24,000 r/min, mass about 17 g."
      },
      {
        "q": "How is the K 15x21x21 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 15 mm (shaft journal), E 21 mm (complement outside diameter, matched by the housing bore) and B 21 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 15x21x21 run on an unhardened shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 15x21x21 be mounted?",
        "a": "Slide the assembly over the ground 15 mm journal with a mounting sleeve, bore the housing to E 21 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K15X21X21",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K15X21X21",
      "K 15x21x21"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K32X37X13",
    "brand": "SKF",
    "manufacturer_designation": "K 32x37x13",
    "series": "K-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 37,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 14.7,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3,
    "max_rpm": 14000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 14000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 32x37x13 in the K series of needle roller and cage assemblies: needle rollers caged at 32×37×13 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 32 (shaft journal), E 37 (assembly outside diameter) and B 13 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 14,000 r/min limiting speed assumes a precision ground journal and bore. Speed planning separates the two ceilings: 13,000 r/min thermal reference and 14,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 32 mm seat. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 13 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 14.7/25.5 kN ratings are SKF catalogue values for this exact execution (K 32x37x13); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 14.7/25.5 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 32x37x13 have?",
        "a": "A K 32x37x13 measures 32 mm bore/Fw × 37 mm outside diameter × 13 mm width (1.26 × 1.457 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 14.7 kN, static C0 25.5 kN, fatigue limit Pu 3 kN, limiting speed 14,000 r/min, reference speed 13,000 r/min, mass about 18 g."
      },
      {
        "q": "What does K 32x37x13 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 32 mm (shaft journal), E 37 mm (complement outside diameter, matched by the housing bore) and B 13 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 32x37x13 need a hardened and ground shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 32x37x13?",
        "a": "Slide the assembly over the ground 32 mm journal with a mounting sleeve, bore the housing to E 37 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K32X37X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K32X37X13",
      "K 32x37x13"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K32X37X17",
    "brand": "SKF",
    "manufacturer_designation": "K 32x37x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 37,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 35.5,
    "fatigue_load_limit_kN": 4.25,
    "max_rpm": 14000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 14000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 32x37x17: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 32 × E 37 × B 17 mm. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 32 (shaft journal), E 37 (assembly outside diameter) and B 17 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 14,000 r/min limiting speed assumes a precision ground journal and bore. Speed planning separates the two ceilings: 13,000 r/min thermal reference and 14,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 32 mm seat. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 17 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 32x37x17 shares its 32×37×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 19/35.5 kN ratings and 19 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does K 32x37x17 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 32 mm (shaft journal), E 37 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 32x37x17 need a hardened and ground shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 32x37x17?",
        "a": "Slide the assembly over the ground 32 mm journal with a mounting sleeve, bore the housing to E 37 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 32x37x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K32X37X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K32X37X17",
      "K 32x37x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K32X38X20",
    "brand": "SKF",
    "manufacturer_designation": "K 32x38x20",
    "series": "K-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 38,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.1,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 32x38x20 in the K series of needle roller and cage assemblies: needle rollers caged at 32×38×20 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. The designation numbers of K 32x38x20 state the three machine-seat dimensions — 32 mm journal, 38 mm bore-side complement diameter, 20 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Selection arithmetic: C 25.1 kN against C0 45 kN gives a C0/C ratio of 1.79, and the 5.6 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 20 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 32 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 25.1/45 kN ratings are SKF catalogue values for this exact execution (K 32x38x20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 25.1/45 kN ratings and 30 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the K 32x38x20?",
        "a": "A K 32x38x20 measures 32 mm bore/Fw × 38 mm outside diameter × 20 mm width (1.26 × 1.496 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.1 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 30 g."
      },
      {
        "q": "How is the K 32x38x20 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 32 mm (shaft journal), E 38 mm (complement outside diameter, matched by the housing bore) and B 20 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 32x38x20 run on an unhardened shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 32x38x20 be mounted?",
        "a": "Slide the assembly over the ground 32 mm journal with a mounting sleeve, bore the housing to E 38 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K32X38X20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K32X38X20",
      "K 32x38x20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K32X40X25",
    "brand": "SKF",
    "manufacturer_designation": "K 32x40x25",
    "series": "K-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 40,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 35.8,
    "static_load_kN": 58.5,
    "fatigue_load_limit_kN": 7.2,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 49,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 32x40x25 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 32 mm hardened shaft journal and the 40 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. The designation numbers of K 32x40x25 state the three machine-seat dimensions — 32 mm journal, 40 mm bore-side complement diameter, 25 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. For life calculation, the 35.8/58.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: grind the 32 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 40 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 32 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 35.8/58.5 kN ratings are SKF catalogue values for this exact execution (K 32x40x25); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 35.8/58.5 kN ratings and 49 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 32x40x25 run on an unhardened shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 32x40x25 be mounted?",
        "a": "Slide the assembly over the ground 32 mm journal with a mounting sleeve, bore the housing to E 40 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 32x40x25?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 32 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 32x40x25?",
        "a": "A K 32x40x25 measures 32 mm bore/Fw × 40 mm outside diameter × 25 mm width (1.26 × 1.575 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 35.8 kN, static C0 58.5 kN, fatigue limit Pu 7.2 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 49 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K32X40X25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K32X40X25",
      "K 32x40x25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K35X40X13",
    "brand": "SKF",
    "manufacturer_designation": "K 35x40x13",
    "series": "K-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 40,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.4,
    "static_load_kN": 28,
    "fatigue_load_limit_kN": 3.25,
    "max_rpm": 13000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 13000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 35x40x13 is a caged needle roller set, not a complete bearing: paired with a 58–64 HRC ground journal of 35 mm and a housing bore of 40 mm, it forms a full rolling bearing with the smallest possible radial space demand. K 35×40×13 is a boundary plan, not an envelope: the assembly has no rings, so E 40 mm is the needle set diameter the housing bore must match, and the 35 mm journal must be ground and hardened. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: grind the 35 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 40 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 12,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 15.4/28 kN ratings and 19 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 35x40x13 need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 35x40x13?",
        "a": "Slide the assembly over the ground 35 mm journal with a mounting sleeve, bore the housing to E 40 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 35x40x13 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 35x40x13 have?",
        "a": "A K 35x40x13 measures 35 mm bore/Fw × 40 mm outside diameter × 13 mm width (1.378 × 1.575 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.4 kN, static C0 28 kN, fatigue limit Pu 3.25 kN, limiting speed 13,000 r/min, reference speed 12,000 r/min, mass about 19 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K35X40X13",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K35X40X13",
      "K 35x40x13"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K35X40X17",
    "brand": "SKF",
    "manufacturer_designation": "K 35x40x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 40,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19.8,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.65,
    "max_rpm": 13000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 13000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 35x40x17 in the K series of needle roller and cage assemblies: needle rollers caged at 35×40×17 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 35×40×17 is a boundary plan, not an envelope: the assembly has no rings, so E 40 mm is the needle set diameter the housing bore must match, and the 35 mm journal must be ground and hardened. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: grind the 35 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 40 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 19.8/39 kN ratings are SKF catalogue values for this exact execution (K 35x40x17); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 19.8/39 kN ratings and 21 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a K 35x40x17?",
        "a": "Slide the assembly over the ground 35 mm journal with a mounting sleeve, bore the housing to E 40 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 35x40x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 35x40x17 have?",
        "a": "A K 35x40x17 measures 35 mm bore/Fw × 40 mm outside diameter × 17 mm width (1.378 × 1.575 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19.8 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 12,000 r/min, mass about 21 g."
      },
      {
        "q": "What does K 35x40x17 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 35 mm (shaft journal), E 40 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K35X40X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K35X40X17",
      "K 35x40x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K35X40X27-TN",
    "brand": "SKF",
    "manufacturer_designation": "K 35x40x27 TN",
    "series": "K-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 40,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 23.8,
    "static_load_kN": 49,
    "fatigue_load_limit_kN": 6,
    "max_rpm": 13000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 13000,
    "weight_g": 39,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 35x40x27 TN: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 35 × E 40 × B 27 mm. K 35×40×27 is a boundary plan, not an envelope: the assembly has no rings, so E 40 mm is the needle set diameter the housing bore must match, and the 35 mm journal must be ground and hardened. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Catalogue mass 39 g at 35×40×27 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 35 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 40 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 12,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 23.8/49 kN ratings and 39 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 35x40x27 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 35x40x27 TN have?",
        "a": "A K 35x40x27 TN measures 35 mm bore/Fw × 40 mm outside diameter × 27 mm width (1.378 × 1.575 × 1.063 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.8 kN, static C0 49 kN, fatigue limit Pu 6 kN, limiting speed 13,000 r/min, reference speed 12,000 r/min, mass about 39 g."
      },
      {
        "q": "What does K 35x40x27 TN mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 35 mm (shaft journal), E 40 mm (complement outside diameter, matched by the housing bore) and B 27 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 35x40x27 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K35X40X27",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K35X40X27-TN",
      "K 35x40x27 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K35X42X16",
    "brand": "SKF",
    "manufacturer_designation": "K 35x42x16",
    "series": "K-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 42,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 37.5,
    "fatigue_load_limit_kN": 4.5,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 35x42x16: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 35 × E 42 × B 16 mm. K 35×42×16 is a boundary plan, not an envelope: the assembly has no rings, so E 42 mm is the needle set diameter the housing bore must match, and the 35 mm journal must be ground and hardened. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. For life calculation, the 23.3/37.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: grind the 35 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 42 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 23.3/37.5 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 35x42x16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 35x42x16 have?",
        "a": "A K 35x42x16 measures 35 mm bore/Fw × 42 mm outside diameter × 16 mm width (1.378 × 1.654 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 37.5 kN, fatigue limit Pu 4.5 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 34 g."
      },
      {
        "q": "What does K 35x42x16 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 35 mm (shaft journal), E 42 mm (complement outside diameter, matched by the housing bore) and B 16 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 35x42x16 need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K35X42X16",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K35X42X16",
      "K 35x42x16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K35X42X18",
    "brand": "SKF",
    "manufacturer_designation": "K 35x42x18",
    "series": "K-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 42,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 44,
    "fatigue_load_limit_kN": 5.3,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 35x42x18 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 35 mm hardened shaft journal and the 42 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 35 (shaft journal), E 42 (assembly outside diameter) and B 18 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. For life calculation, the 26.4/44 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: grind the 35 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 42 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 35x42x18 shares its 35×42×18 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 26.4/44 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 35x42x18 need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 35x42x18?",
        "a": "Slide the assembly over the ground 35 mm journal with a mounting sleeve, bore the housing to E 42 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 35x42x18 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 35x42x18 have?",
        "a": "A K 35x42x18 measures 35 mm bore/Fw × 42 mm outside diameter × 18 mm width (1.378 × 1.654 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 44 kN, fatigue limit Pu 5.3 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 34 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K35X42X18",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K35X42X18",
      "K 35x42x18"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K35X45X20",
    "brand": "SKF",
    "manufacturer_designation": "K 35x45x20",
    "series": "K-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 45,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 35.2,
    "static_load_kN": 50,
    "fatigue_load_limit_kN": 6.2,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 56,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "The K assembly K 35x45x20 is the lowest-radial-section rolling bearing available for a 35 mm shaft: only the 20 mm wide cage-and-roller set sits between journal and bore, giving extreme compactness where even a drawn cup is too heavy a section. The designation numbers of K 35x45x20 state the three machine-seat dimensions — 35 mm journal, 45 mm bore-side complement diameter, 20 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Speed planning separates the two ceilings: 11,000 r/min thermal reference and 12,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 35 mm seat. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: K 35x45x20 shares its 35×45×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 35.2/50 kN ratings and 56 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 35x45x20 run on an unhardened shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 35x45x20 be mounted?",
        "a": "Slide the assembly over the ground 35 mm journal with a mounting sleeve, bore the housing to E 45 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 35x45x20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 35x45x20?",
        "a": "A K 35x45x20 measures 35 mm bore/Fw × 45 mm outside diameter × 20 mm width (1.378 × 1.772 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 35.2 kN, static C0 50 kN, fatigue limit Pu 6.2 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 56 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K35X45X20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K35X45X20",
      "K 35x45x20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K37X42X17",
    "brand": "SKF",
    "manufacturer_designation": "K 37x42x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 37,
    "D_mm": 42,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.2,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 37x42x17 in the K series of needle roller and cage assemblies: needle rollers caged at 37×42×17 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 37x42x17, Fw×E×B reads directly as journal 37 mm, complement diameter 42 mm and cage width 17 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. For life calculation, the 21.6/43 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 17 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 37 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 37 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 21.6/43 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the K 37x42x17 be mounted?",
        "a": "Slide the assembly over the ground 37 mm journal with a mounting sleeve, bore the housing to E 42 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 37x42x17?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 37 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 37x42x17?",
        "a": "A K 37x42x17 measures 37 mm bore/Fw × 42 mm outside diameter × 17 mm width (1.457 × 1.654 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 43 kN, fatigue limit Pu 5.2 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 22 g."
      },
      {
        "q": "How is the K 37x42x17 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 37 mm (shaft journal), E 42 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K37X42X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K37X42X17",
      "K 37x42x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K38X43X17",
    "brand": "SKF",
    "manufacturer_designation": "K 38x43x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 38,
    "D_mm": 43,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19.8,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.65,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 38x43x17 in the K series of needle roller and cage assemblies: needle rollers caged at 38×43×17 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. K 38×43×17 is a boundary plan, not an envelope: the assembly has no rings, so E 43 mm is the needle set diameter the housing bore must match, and the 38 mm journal must be ground and hardened. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. For life calculation, the 19.8/39 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: grind the 38 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 43 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 38 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 38 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 38x43x17 shares its 38×43×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 19.8/39 kN ratings and 29 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a K 38x43x17?",
        "a": "Slide the assembly over the ground 38 mm journal with a mounting sleeve, bore the housing to E 43 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 38x43x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 38x43x17 have?",
        "a": "A K 38x43x17 measures 38 mm bore/Fw × 43 mm outside diameter × 17 mm width (1.496 × 1.693 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19.8 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 29 g."
      },
      {
        "q": "What does K 38x43x17 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 38 mm (shaft journal), E 43 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K38X43X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K38X43X17",
      "K 38x43x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K38X46X32",
    "brand": "SKF",
    "manufacturer_designation": "K 38x46x32",
    "series": "K-series",
    "type": "needle",
    "d_mm": 38,
    "D_mm": 46,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 52.3,
    "static_load_kN": 100,
    "fatigue_load_limit_kN": 12.5,
    "max_rpm": 12000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 12000,
    "weight_g": 76,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 38x46x32 is a caged needle roller set, not a complete bearing: paired with a 58–64 HRC ground journal of 38 mm and a housing bore of 46 mm, it forms a full rolling bearing with the smallest possible radial space demand. In the K code K 38x46x32, Fw×E×B reads directly as journal 38 mm, complement diameter 46 mm and cage width 32 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Selection arithmetic: C 52.3 kN against C0 100 kN gives a C0/C ratio of 1.91, and the 12.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 32 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 38 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 38 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 52.3/100 kN ratings and 76 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the K 38x46x32 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 38 mm (shaft journal), E 46 mm (complement outside diameter, matched by the housing bore) and B 32 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 38x46x32 run on an unhardened shaft?",
        "a": "No. In this execution the 38 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 38x46x32 be mounted?",
        "a": "Slide the assembly over the ground 38 mm journal with a mounting sleeve, bore the housing to E 46 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 38x46x32?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 38 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K38X46X32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K38X46X32",
      "K 38x46x32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K40X45X17",
    "brand": "SKF",
    "manufacturer_designation": "K 40x45x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 45,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 20.5,
    "static_load_kN": 41.5,
    "fatigue_load_limit_kN": 5,
    "max_rpm": 12000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 12000,
    "weight_g": 31,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 40x45x17 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 40 mm hardened shaft journal and the 45 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 40 (shaft journal), E 45 (assembly outside diameter) and B 17 (width) in millimetres — the machine parts complete the bearing. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. For life calculation, the 20.5/41.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 17 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 10,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 20.5/41.5 kN ratings and 31 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 40x45x17 need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 40x45x17?",
        "a": "Slide the assembly over the ground 40 mm journal with a mounting sleeve, bore the housing to E 45 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 40x45x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 40x45x17 have?",
        "a": "A K 40x45x17 measures 40 mm bore/Fw × 45 mm outside diameter × 17 mm width (1.575 × 1.772 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 20.5 kN, static C0 41.5 kN, fatigue limit Pu 5 kN, limiting speed 12,000 r/min, reference speed 10,000 r/min, mass about 31 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K40X45X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K40X45X17",
      "K 40x45x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K40X45X27",
    "brand": "SKF",
    "manufacturer_designation": "K 40x45x27",
    "series": "K-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 45,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.4,
    "static_load_kN": 73.5,
    "fatigue_load_limit_kN": 9,
    "max_rpm": 12000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 12000,
    "weight_g": 46,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 40x45x27: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 40 × E 45 × B 27 mm. In the K code K 40x45x27, Fw×E×B reads directly as journal 40 mm, complement diameter 45 mm and cage width 27 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. For life calculation, the 31.4/73.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 31.4/73.5 kN ratings are SKF catalogue values for this exact execution (K 40x45x27); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 31.4/73.5 kN ratings and 46 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a K 40x45x27?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 40x45x27?",
        "a": "A K 40x45x27 measures 40 mm bore/Fw × 45 mm outside diameter × 27 mm width (1.575 × 1.772 × 1.063 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.4 kN, static C0 73.5 kN, fatigue limit Pu 9 kN, limiting speed 12,000 r/min, reference speed 10,000 r/min, mass about 46 g."
      },
      {
        "q": "How is the K 40x45x27 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 40 mm (shaft journal), E 45 mm (complement outside diameter, matched by the housing bore) and B 27 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 40x45x27 run on an unhardened shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K40X45X27",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K40X45X27",
      "K 40x45x27"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K40X48X20",
    "brand": "SKF",
    "manufacturer_designation": "K 40x48x20",
    "series": "K-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 48,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 34.7,
    "static_load_kN": 58.5,
    "fatigue_load_limit_kN": 7.35,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 49,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 40x48x20 appears as a needle roller and cage assembly with complement diameter E 48 mm and width 20 mm — a self-contained roller set that turns a 40 mm shaft and its housing into a complete bearing. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 40 (shaft journal), E 48 (assembly outside diameter) and B 20 (width) in millimetres — the machine parts complete the bearing. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. Speed planning separates the two ceilings: 10,000 r/min thermal reference and 11,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 40 mm seat. Mounting: grind the 40 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 48 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 10,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 34.7/58.5 kN ratings and 49 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does K 40x48x20 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 40 mm (shaft journal), E 48 mm (complement outside diameter, matched by the housing bore) and B 20 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 40x48x20 need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 40x48x20?",
        "a": "Slide the assembly over the ground 40 mm journal with a mounting sleeve, bore the housing to E 48 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 40x48x20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K40X48X20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K40X48X20",
      "K 40x48x20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K42X47X17",
    "brand": "SKF",
    "manufacturer_designation": "K 42x47x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 47,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 20.9,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.2,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 42x47x17 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 42 mm hardened shaft journal and the 47 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. K 42×47×17 is a boundary plan, not an envelope: the assembly has no rings, so E 47 mm is the needle set diameter the housing bore must match, and the 42 mm journal must be ground and hardened. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. For life calculation, the 20.9/43 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 20.9/43 kN ratings are SKF catalogue values for this exact execution (K 42x47x17); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 20.9/43 kN ratings and 32 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 42x47x17 need a hardened and ground shaft?",
        "a": "No. In this execution the 42 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 42x47x17?",
        "a": "Slide the assembly over the ground 42 mm journal with a mounting sleeve, bore the housing to E 47 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 42x47x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 42x47x17 have?",
        "a": "A K 42x47x17 measures 42 mm bore/Fw × 47 mm outside diameter × 17 mm width (1.654 × 1.85 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 20.9 kN, static C0 43 kN, fatigue limit Pu 5.2 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 32 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K42X47X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K42X47X17",
      "K 42x47x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K42X50X20",
    "brand": "SKF",
    "manufacturer_designation": "K 42x50x20",
    "series": "K-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 50,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 33.6,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 42x50x20 denotes a needle roller and cage assembly for a 42 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 20 mm width is all the radial room it needs. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 42 (shaft journal), E 50 (assembly outside diameter) and B 20 (width) in millimetres — the machine parts complete the bearing. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Catalogue mass 53 g at 42×50×20 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 42 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 50 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 42x50x20 shares its 42×50×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 33.6/57 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a K 42x50x20?",
        "a": "Slide the assembly over the ground 42 mm journal with a mounting sleeve, bore the housing to E 50 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 42x50x20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 42x50x20 have?",
        "a": "A K 42x50x20 measures 42 mm bore/Fw × 50 mm outside diameter × 20 mm width (1.654 × 1.969 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 33.6 kN, static C0 57 kN, fatigue limit Pu 7.1 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 53 g."
      },
      {
        "q": "What does K 42x50x20 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 42 mm (shaft journal), E 50 mm (complement outside diameter, matched by the housing bore) and B 20 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K42X50X20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K42X50X20",
      "K 42x50x20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K43X48X17",
    "brand": "SKF",
    "manufacturer_designation": "K 43x48x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 43,
    "D_mm": 48,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 20.9,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.2,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 43x48x17 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 43 mm hardened shaft journal and the 48 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 43 (shaft journal), E 48 (assembly outside diameter) and B 17 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 11,000 r/min limiting speed assumes a precision ground journal and bore. The 30 g catalogue mass and 2.5 mm radial section ((48−43)/2) frame a rating of about 0.49 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 17 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 43 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 43 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 20.9/43 kN ratings are SKF catalogue values for this exact execution (K 43x48x17); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 20.9/43 kN ratings and 30 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 43x48x17 need a hardened and ground shaft?",
        "a": "No. In this execution the 43 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 43x48x17?",
        "a": "Slide the assembly over the ground 43 mm journal with a mounting sleeve, bore the housing to E 48 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 43x48x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 43x48x17 have?",
        "a": "A K 43x48x17 measures 43 mm bore/Fw × 48 mm outside diameter × 17 mm width (1.693 × 1.89 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 20.9 kN, static C0 43 kN, fatigue limit Pu 5.2 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 30 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K43X48X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K43X48X17",
      "K 43x48x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K45X50X17",
    "brand": "SKF",
    "manufacturer_designation": "K 45x50x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 50,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 46.5,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 45x50x17 appears as a needle roller and cage assembly with complement diameter E 50 mm and width 17 mm — a self-contained roller set that turns a 45 mm shaft and its housing into a complete bearing. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 45 (shaft journal), E 50 (assembly outside diameter) and B 17 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Selection arithmetic: C 21.6 kN against C0 46.5 kN gives a C0/C ratio of 2.15, and the 5.6 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 17 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 9,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 45 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 21.6/46.5 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 45x50x17 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 45x50x17 have?",
        "a": "A K 45x50x17 measures 45 mm bore/Fw × 50 mm outside diameter × 17 mm width (1.772 × 1.969 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 46.5 kN, fatigue limit Pu 5.6 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 34 g."
      },
      {
        "q": "What does K 45x50x17 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 45 mm (shaft journal), E 50 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 45x50x17 need a hardened and ground shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K45X50X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K45X50X17",
      "K 45x50x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K45X50X27",
    "brand": "SKF",
    "manufacturer_designation": "K 45x50x27",
    "series": "K-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 50,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 33,
    "static_load_kN": 81.5,
    "fatigue_load_limit_kN": 10,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 45x50x27 in the K series of needle roller and cage assemblies: needle rollers caged at 45×50×27 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 45x50x27, Fw×E×B reads directly as journal 45 mm, complement diameter 50 mm and cage width 27 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Selection arithmetic: C 33 kN against C0 81.5 kN gives a C0/C ratio of 2.47, and the 10 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 45 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 33/81.5 kN ratings are SKF catalogue values for this exact execution (K 45x50x27); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 33/81.5 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the K 45x50x27 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 45 mm (shaft journal), E 50 mm (complement outside diameter, matched by the housing bore) and B 27 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 45x50x27 run on an unhardened shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 45x50x27 be mounted?",
        "a": "Slide the assembly over the ground 45 mm journal with a mounting sleeve, bore the housing to E 50 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 45x50x27?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K45X50X27",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K45X50X27",
      "K 45x50x27"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K45X53X28",
    "brand": "SKF",
    "manufacturer_designation": "K 45x53x28",
    "series": "K-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 53,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 49.5,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.2,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 81,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 45x53x28 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 45 mm hardened shaft journal and the 53 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 45 (shaft journal), E 53 (assembly outside diameter) and B 28 (width) in millimetres — the machine parts complete the bearing. The TN suffix marks a glass fibre reinforced PA66 cage snapping the rollers in place — lighter and quieter than steel; assemblies are also supplied unmarked with steel cages for higher temperature duty. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: grind the 45 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 53 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: K 45x53x28 shares its 45×53×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 49.5/98 kN ratings and 81 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the K 45x53x28 have?",
        "a": "A K 45x53x28 measures 45 mm bore/Fw × 53 mm outside diameter × 28 mm width (1.772 × 2.087 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 49.5 kN, static C0 98 kN, fatigue limit Pu 12.2 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 81 g."
      },
      {
        "q": "What does K 45x53x28 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 45 mm (shaft journal), E 53 mm (complement outside diameter, matched by the housing bore) and B 28 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 45x53x28 need a hardened and ground shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 45x53x28?",
        "a": "Slide the assembly over the ground 45 mm journal with a mounting sleeve, bore the housing to E 53 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K45X53X28",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K45X53X28",
      "K 45x53x28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K47X52X17",
    "brand": "SKF",
    "manufacturer_designation": "K 47x52x17",
    "series": "K-series",
    "type": "needle",
    "d_mm": 47,
    "D_mm": 52,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.4,
    "static_load_kN": 49,
    "fatigue_load_limit_kN": 6,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 35,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 47x52x17 appears as a needle roller and cage assembly with complement diameter E 52 mm and width 17 mm — a self-contained roller set that turns a 47 mm shaft and its housing into a complete bearing. The designation numbers of K 47x52x17 state the three machine-seat dimensions — 47 mm journal, 52 mm bore-side complement diameter, 17 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 10,000 r/min limiting speed assumes a precision ground journal and bore. Catalogue mass 35 g at 47×52×17 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 47 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 47 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 47 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 22.4/49 kN ratings are SKF catalogue values for this exact execution (K 47x52x17); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 22.4/49 kN ratings and 35 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a K 47x52x17?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 47 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 47x52x17?",
        "a": "A K 47x52x17 measures 47 mm bore/Fw × 52 mm outside diameter × 17 mm width (1.85 × 2.047 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.4 kN, static C0 49 kN, fatigue limit Pu 6 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 35 g."
      },
      {
        "q": "How is the K 47x52x17 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 47 mm (shaft journal), E 52 mm (complement outside diameter, matched by the housing bore) and B 17 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 47x52x17 run on an unhardened shaft?",
        "a": "No. In this execution the 47 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K47X52X17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K47X52X17",
      "K 47x52x17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K50X55X20",
    "brand": "SKF",
    "manufacturer_designation": "K 50x55x20",
    "series": "K-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.5,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 7.2,
    "max_rpm": 9500,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 9500,
    "weight_g": 43,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "K 50x55x20 is a needle roller and cage assembly to DIN 5402: a complement of needle rollers held by a lightweight cage, with no inner or outer ring of its own — the 50 mm hardened shaft journal and the 55 mm housing bore serve as the raceways, as tabulated in SKF catalogue PUB BU/P1 17000. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 50 (shaft journal), E 55 (assembly outside diameter) and B 20 (width) in millimetres — the machine parts complete the bearing. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 9,500 r/min limiting speed assumes a precision ground journal and bore. Catalogue mass 43 g at 50×55×20 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 50 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 55 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 8,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 25.5/60 kN ratings and 43 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 50x55x20 need a hardened and ground shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 50x55x20?",
        "a": "Slide the assembly over the ground 50 mm journal with a mounting sleeve, bore the housing to E 55 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 50x55x20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 50x55x20 have?",
        "a": "A K 50x55x20 measures 50 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.969 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 60 kN, fatigue limit Pu 7.2 kN, limiting speed 9,500 r/min, reference speed 8,500 r/min, mass about 43 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K50X55X20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K50X55X20",
      "K 50x55x20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K50X55X30",
    "brand": "SKF",
    "manufacturer_designation": "K 50x55x30",
    "series": "K-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 55,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 37.4,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12,
    "max_rpm": 9500,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 9500,
    "weight_g": 65,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "For pivots and crank pins where every millimetre of radial height counts, SKF supplies K 50x55x30: needle rollers in a pressed cage (DIN 5402 boundary plan), dimensioned Fw 50 × E 55 × B 30 mm. In the K code K 50x55x30, Fw×E×B reads directly as journal 50 mm, complement diameter 55 mm and cage width 30 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 9,500 r/min limiting speed assumes a precision ground journal and bore. Catalogue mass 65 g at 50×55×30 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 30 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 37.4/98 kN ratings are SKF catalogue values for this exact execution (K 50x55x30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 37.4/98 kN ratings and 65 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a K 50x55x30?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 50x55x30?",
        "a": "A K 50x55x30 measures 50 mm bore/Fw × 55 mm outside diameter × 30 mm width (1.969 × 2.165 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 37.4 kN, static C0 98 kN, fatigue limit Pu 12 kN, limiting speed 9,500 r/min, reference speed 8,500 r/min, mass about 65 g."
      },
      {
        "q": "How is the K 50x55x30 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 50 mm (shaft journal), E 55 mm (complement outside diameter, matched by the housing bore) and B 30 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 50x55x30 run on an unhardened shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K50X55X30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K50X55X30",
      "K 50x55x30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K50X57X18",
    "brand": "SKF",
    "manufacturer_designation": "K 50x57x18",
    "series": "K-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 57,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 64,
    "fatigue_load_limit_kN": 7.8,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 47,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 50x57x18 in the K series of needle roller and cage assemblies: needle rollers caged at 50×57×18 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 50 (shaft journal), E 57 (assembly outside diameter) and B 18 (width) in millimetres — the machine parts complete the bearing. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The assembly is drawn on over a mounting sleeve that spreads the load around all rollers; never drive it home against the cage face, and retain it with a washer whose OD spans the cage, not the rollers.",
    "applications": [
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 31.9/64 kN ratings and 47 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the K 50x57x18 need a hardened and ground shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a K 50x57x18?",
        "a": "Slide the assembly over the ground 50 mm journal with a mounting sleeve, bore the housing to E 57 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "Is the K 50x57x18 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 50x57x18 have?",
        "a": "A K 50x57x18 measures 50 mm bore/Fw × 57 mm outside diameter × 18 mm width (1.969 × 2.244 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 64 kN, fatigue limit Pu 7.8 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 47 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K50X57X18",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K50X57X18",
      "K 50x57x18"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K50X58X25",
    "brand": "SKF",
    "manufacturer_designation": "K 50x58x25",
    "series": "K-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 58,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 41.8,
    "static_load_kN": 81.5,
    "fatigue_load_limit_kN": 10.2,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 90,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 50x58x25 appears as a needle roller and cage assembly with complement diameter E 58 mm and width 25 mm — a self-contained roller set that turns a 50 mm shaft and its housing into a complete bearing. The designation numbers of K 50x58x25 state the three machine-seat dimensions — 50 mm journal, 58 mm bore-side complement diameter, 25 mm width — which is why ordering errors here show up as a sloppy or seized fit, not as a returned box. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 9,000 r/min limiting speed assumes a precision ground journal and bore. For life calculation, the 41.8/81.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 25 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: K 50x58x25 shares its 50×58×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 41.8/81.5 kN ratings and 90 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the K 50x58x25 run on an unhardened shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 50x58x25 be mounted?",
        "a": "Slide the assembly over the ground 50 mm journal with a mounting sleeve, bore the housing to E 58 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 50x58x25?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 50x58x25?",
        "a": "A K 50x58x25 measures 50 mm bore/Fw × 58 mm outside diameter × 25 mm width (1.969 × 2.283 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 41.8 kN, static C0 81.5 kN, fatigue limit Pu 10.2 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 90 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K50X58X25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K50X58X25",
      "K 50x58x25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K55X60X20",
    "brand": "SKF",
    "manufacturer_designation": "K 55x60x20",
    "series": "K-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 60,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27,
    "static_load_kN": 67,
    "fatigue_load_limit_kN": 8.15,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000 ch. 7.1, K 55x60x20 appears as a needle roller and cage assembly with complement diameter E 60 mm and width 20 mm — a self-contained roller set that turns a 55 mm shaft and its housing into a complete bearing. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 55 (shaft journal), E 60 (assembly outside diameter) and B 20 (width) in millimetres — the machine parts complete the bearing. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. The 40 g catalogue mass and 2.5 mm radial section ((60−55)/2) frame a rating of about 0.49 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: grind the 55 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 60 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 27/67 kN ratings and 40 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 55x60x20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 55x60x20 have?",
        "a": "A K 55x60x20 measures 55 mm bore/Fw × 60 mm outside diameter × 20 mm width (2.165 × 2.362 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27 kN, static C0 67 kN, fatigue limit Pu 8.15 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 40 g."
      },
      {
        "q": "What does K 55x60x20 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 55 mm (shaft journal), E 60 mm (complement outside diameter, matched by the housing bore) and B 20 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 55x60x20 need a hardened and ground shaft?",
        "a": "No. In this execution the 55 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K55X60X20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K55X60X20",
      "K 55x60x20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K55X60X30",
    "brand": "SKF",
    "manufacturer_designation": "K 55x60x30",
    "series": "K-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 60,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.6,
    "static_load_kN": 108,
    "fatigue_load_limit_kN": 13.4,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 71,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 55x60x30 in the K series of needle roller and cage assemblies: needle rollers caged at 55×60×30 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 55x60x30, Fw×E×B reads directly as journal 55 mm, complement diameter 60 mm and cage width 30 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. No suffix on the order number means the standard single-row assembly; the polymer TN cage version is the usual choice for grease-lubricated pivots where noise matters. The 71 g catalogue mass and 2.5 mm radial section ((60−55)/2) frame a rating of about 0.72 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 30 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles",
      "planetary gear pins in compact transmissions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 39.6/108 kN ratings are SKF catalogue values for this exact execution (K 55x60x30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 39.6/108 kN ratings and 71 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the K 55x60x30 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 55 mm (shaft journal), E 60 mm (complement outside diameter, matched by the housing bore) and B 30 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Can the K 55x60x30 run on an unhardened shaft?",
        "a": "No. In this execution the 55 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the K 55x60x30 be mounted?",
        "a": "Slide the assembly over the ground 55 mm journal with a mounting sleeve, bore the housing to E 60 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 55x60x30?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K55X60X30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K55X60X30",
      "K 55x60x30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K55X62X18",
    "brand": "SKF",
    "manufacturer_designation": "K 55x62x18",
    "series": "K-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 62,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 34.1,
    "static_load_kN": 71,
    "fatigue_load_limit_kN": 8.5,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF catalogue number K 55x62x18 denotes a needle roller and cage assembly for a 55 mm shaft seat — the cage spaces the rollers, the machine parts provide both raceways, and the 18 mm width is all the radial room it needs. Reading the designation: K marks the needle roller and cage assembly, the three numbers give Fw 55 (shaft journal), E 62 (assembly outside diameter) and B 18 (width) in millimetres — the machine parts complete the bearing. Because there are no rings, execution differences live in the cage: TN polymer cages reduce friction and noise, while the basic steel cage tolerates higher operating temperatures up to the lubricant limit. Speed planning separates the two ceilings: 7,500 r/min thermal reference and 8,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 55 mm seat. Lubrication reaches both raceways through the open cage windows; grease the bore and journal before assembly, since after fitting the 18 mm narrow cage cannot be relubricated through a closed housing.",
    "applications": [
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins",
      "hinge and pivot joints in printing and textile machinery",
      "universal joint crosses on commercial vehicles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 34.1/71 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the K 55x62x18 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the K 55x62x18 have?",
        "a": "A K 55x62x18 measures 55 mm bore/Fw × 62 mm outside diameter × 18 mm width (2.165 × 2.441 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 34.1 kN, static C0 71 kN, fatigue limit Pu 8.5 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 52 g."
      },
      {
        "q": "What does K 55x62x18 mean in SKF part numbering?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 55 mm (shaft journal), E 62 mm (complement outside diameter, matched by the housing bore) and B 18 mm width. TN marks the glass fibre reinforced PA66 cage."
      },
      {
        "q": "Does the K 55x62x18 need a hardened and ground shaft?",
        "a": "No. In this execution the 55 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K55X62X18",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K55X62X18",
      "K 55x62x18"
    ],
    "locale_variants": {}
  },
  {
    "sku": "K55X63X32",
    "brand": "SKF",
    "manufacturer_designation": "K 55x63x32",
    "series": "K-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 63,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 59.4,
    "static_load_kN": 129,
    "fatigue_load_limit_kN": 16.3,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 102,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 5402",
    "naming_rule_text": "SKF lists K 55x63x32 in the K series of needle roller and cage assemblies: needle rollers caged at 55×63×32 mm, designed to run directly on a ground, hardened shaft and inside a machined housing bore. In the K code K 55x63x32, Fw×E×B reads directly as journal 55 mm, complement diameter 63 mm and cage width 32 mm; the housing bore is ground to E with H6/H7 tolerance to complete the outer raceway. SKF supplies these assemblies in single rows as tabulated; the cage quality determines the speed ceiling, and the catalogued 8,500 r/min limiting speed assumes a precision ground journal and bore. Catalogue mass 102 g at 55×63×32 mm makes this one of the highest capacity-per-gram choices in the needle roller and cage assemblies; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: grind the 55 mm journal to the catalogue raceway tolerance after hardening to 58–64 HRC, bore the housing to E 63 mm H6, and slide the assembly in axially — pressing through the cage distorts it and locks the rollers.",
    "applications": [
      "planetary gear pins in compact transmissions",
      "connecting rods of small compressors where radial height is critical",
      "rocker arm and rocker pin pivots on camshafts",
      "pump and gearbox idler gears running on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 59.4/129 kN ratings and 102 g mass are SKF catalogue values transcribed from ch. 7.1 of PUB BU/P1 17000 (PDF table page 618); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the K 55x63x32 be mounted?",
        "a": "Slide the assembly over the ground 55 mm journal with a mounting sleeve, bore the housing to E 63 mm, and retain with a washer spanning the cage. Never press against the cage or rotate before the bearing is lubricated and loaded."
      },
      {
        "q": "What limits the service life of a K 55x63x32?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the K 55x63x32?",
        "a": "A K 55x63x32 measures 55 mm bore/Fw × 63 mm outside diameter × 32 mm width (2.165 × 2.48 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 59.4 kN, static C0 129 kN, fatigue limit Pu 16.3 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 102 g."
      },
      {
        "q": "How is the K 55x63x32 designation read?",
        "a": "K = needle roller and cage assembly (DIN 5402); the three figures give Fw 55 mm (shaft journal), E 63 mm (complement outside diameter, matched by the housing bore) and B 32 mm width. TN marks the glass fibre reinforced PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "K55X63X32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.1 needle roller and cage assemblies",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "K55X63X32",
      "K 55x63x32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0306-TN",
    "brand": "SKF",
    "manufacturer_designation": "HK 0306 TN",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 3,
    "D_mm": 6.5,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 1.23,
    "static_load_kN": 0.88,
    "fatigue_load_limit_kN": 0.088,
    "max_rpm": 26000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 26000,
    "weight_g": 1,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 0306 TN for housings where machining an outer-ring pocket is uneconomical: the 6.5 mm shell broached from sheet steel press-fits into a plain bore and runs a 3 mm hardened shaft. In HK 0306, Fw = 3 mm names the shaft that becomes the inner raceway and B = 6 mm the cup width; the shell outside diameter 6.5 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. For life calculation, the 1.23/0.88 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "At Fw 3 mm the rolling elements are under two millimetres long — handle the HK 0306 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: HK 0306 TN shares its 3×6.5×6 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 24,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 1.23/0.88 kN ratings and 1 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 0306 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 3 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 1.8 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0306 TN?",
        "a": "A HK 0306 TN measures 3 mm bore/Fw × 6.5 mm outside diameter × 6 mm width (0.118 × 0.256 × 0.236 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 1.23 kN, static C0 0.88 kN, fatigue limit Pu 0.088 kN, limiting speed 26,000 r/min, reference speed 24,000 r/min, mass about 1 g."
      },
      {
        "q": "How is the HK 0306 TN designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 3 mm, the last two the width 6 mm, the shell OD 6.5 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 0306 TN run on an unhardened shaft?",
        "a": "No. In this execution the 3 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0306",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0306-TN",
      "HK 0306 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0408",
    "brand": "SKF",
    "manufacturer_designation": "HK 0408",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 4,
    "D_mm": 8,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 1.76,
    "static_load_kN": 1.37,
    "fatigue_load_limit_kN": 0.14,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 2,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 0408 gives the smallest radial section of any caged needle bearing with its own outer ring: 4 mm Fw, 8 mm OD and 8 mm width, the shell pressed directly into the housing bore. Reading the code: HK marks the open-end drawn cup series, the first two digits (04) give the 4 mm under-roller diameter Fw, the last two (08) the 8 mm width; the 8 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. The 2 g catalogue mass and 2.0 mm radial section ((8−4)/2) frame a rating of about 0.44 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 8 mm section.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "At Fw 4 mm the rolling elements are under two millimetres long — handle the HK 0408 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 0408 shares its 4×8×8 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 1.76/1.37 kN ratings and 2 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 0408?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 0408 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 0408 have?",
        "a": "A HK 0408 measures 4 mm bore/Fw × 8 mm outside diameter × 8 mm width (0.157 × 0.315 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 1.76 kN, static C0 1.37 kN, fatigue limit Pu 0.14 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 2 g."
      },
      {
        "q": "What does HK 0408 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 4 mm, the last two the width 8 mm, the shell OD 8 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0408",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0408",
      "HK 0408"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0509",
    "brand": "SKF",
    "manufacturer_designation": "HK 0509",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 9,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 2.38,
    "static_load_kN": 2.08,
    "fatigue_load_limit_kN": 0.22,
    "max_rpm": 24000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 24000,
    "weight_g": 2,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 5 mm shaft in a thin housing wall, SKF catalogue execution HK 0509 offers a 9 mm wide, 9 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. SKF's HK numbering puts the shaft size first: 05 → Fw 5 mm (the ground, hardened journal), 09 → width 9 mm, with the 9 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Speed planning separates the two ceilings: 22,000 r/min thermal reference and 24,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 5 mm seat. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the HK 0509 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Hardness is load capacity: in families without an inner ring the 5 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 2.38/2.08 kN ratings are SKF catalogue values for this exact execution (HK 0509); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 2.38/2.08 kN ratings and 2 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the HK 0509 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 0509?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 5 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0509?",
        "a": "A HK 0509 measures 5 mm bore/Fw × 9 mm outside diameter × 9 mm width (0.197 × 0.354 × 0.354 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.38 kN, static C0 2.08 kN, fatigue limit Pu 0.22 kN, limiting speed 24,000 r/min, reference speed 22,000 r/min, mass about 2 g."
      },
      {
        "q": "How is the HK 0509 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 5 mm, the last two the width 9 mm, the shell OD 9 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0509",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0509",
      "HK 0509"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0608",
    "brand": "SKF",
    "manufacturer_designation": "HK 0608",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 10,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 2.01,
    "static_load_kN": 1.73,
    "fatigue_load_limit_kN": 0.18,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 2.1,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 0608 denotes a 6×10×8 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. SKF's HK numbering puts the shaft size first: 06 → Fw 6 mm (the ground, hardened journal), 08 → width 8 mm, with the 10 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Selection arithmetic: C 2.01 kN against C0 1.73 kN gives a C0/C ratio of 0.86, and the 0.18 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the HK 0608 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Hardness is load capacity: in families without an inner ring the 6 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 2.01/1.73 kN ratings are SKF catalogue values for this exact execution (HK 0608); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 2.01/1.73 kN ratings and 2.1 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 0608?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 6 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0608?",
        "a": "A HK 0608 measures 6 mm bore/Fw × 10 mm outside diameter × 8 mm width (0.236 × 0.394 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.01 kN, static C0 1.73 kN, fatigue limit Pu 0.18 kN, limiting speed 22,000 r/min, reference speed 20,000 r/min, mass about 2.1 g."
      },
      {
        "q": "How is the HK 0608 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 6 mm, the last two the width 8 mm, the shell OD 10 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 0608 run on an unhardened shaft?",
        "a": "No. In this execution the 6 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0608",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0608",
      "HK 0608"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0609",
    "brand": "SKF",
    "manufacturer_designation": "HK 0609",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 10,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 2.81,
    "static_load_kN": 2.7,
    "fatigue_load_limit_kN": 0.285,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 2.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 0609 for housings where machining an outer-ring pocket is uneconomical: the 10 mm shell broached from sheet steel press-fits into a plain bore and runs a 6 mm hardened shaft. Reading the code: HK marks the open-end drawn cup series, the first two digits (06) give the 6 mm under-roller diameter Fw, the last two (09) the 9 mm width; the 10 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Selection arithmetic: C 2.81 kN against C0 2.7 kN gives a C0/C ratio of 0.96, and the 0.285 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the HK 0609 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Reference and limiting speeds are different limits: the 20,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 6 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 2.81/2.7 kN ratings and 2.5 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 0609?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 0609 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 0609 have?",
        "a": "A HK 0609 measures 6 mm bore/Fw × 10 mm outside diameter × 9 mm width (0.236 × 0.394 × 0.354 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.81 kN, static C0 2.7 kN, fatigue limit Pu 0.285 kN, limiting speed 22,000 r/min, reference speed 20,000 r/min, mass about 2.5 g."
      },
      {
        "q": "What does HK 0609 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 6 mm, the last two the width 9 mm, the shell OD 10 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0609",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0609",
      "HK 0609"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0709",
    "brand": "SKF",
    "manufacturer_designation": "HK 0709",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 11,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 3.03,
    "static_load_kN": 3.05,
    "fatigue_load_limit_kN": 0.325,
    "max_rpm": 22000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 22000,
    "weight_g": 2.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 0709 is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 11 mm outside diameter carrying a caged needle roller set for a 7 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. In HK 0709, Fw = 7 mm names the shaft that becomes the inner raceway and B = 9 mm the cup width; the shell outside diameter 11 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 2.6 g at 7×11×9 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the HK 0709 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: HK 0709 shares its 7×11×9 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 20,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 3.03/3.05 kN ratings and 2.6 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the HK 0709 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 0709?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 7 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0709?",
        "a": "A HK 0709 measures 7 mm bore/Fw × 11 mm outside diameter × 9 mm width (0.276 × 0.433 × 0.354 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.03 kN, static C0 3.05 kN, fatigue limit Pu 0.325 kN, limiting speed 22,000 r/min, reference speed 20,000 r/min, mass about 2.6 g."
      },
      {
        "q": "How is the HK 0709 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 7 mm, the last two the width 9 mm, the shell OD 11 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0709",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0709",
      "HK 0709"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0808",
    "brand": "SKF",
    "manufacturer_designation": "HK 0808",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 12,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 2.7,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.285,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 2.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 0808 is the standard caged drawn cup execution for a 8 mm shaft: ISO 3245 boundary dimensions (8×12×8 mm), open at both ends so the shaft can be pushed through, and rated 2.7 kN dynamic. In HK 0808, Fw = 8 mm names the shaft that becomes the inner raceway and B = 8 mm the cup width; the shell outside diameter 12 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the HK 0808 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: HK 0808 shares its 8×12×8 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 2.7/2.75 kN ratings and 2.7 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 0808?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 8 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0808?",
        "a": "A HK 0808 measures 8 mm bore/Fw × 12 mm outside diameter × 8 mm width (0.315 × 0.472 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.7 kN, static C0 2.75 kN, fatigue limit Pu 0.285 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 2.7 g."
      },
      {
        "q": "How is the HK 0808 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 8 mm, the last two the width 8 mm, the shell OD 12 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 0808 run on an unhardened shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0808",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0808",
      "HK 0808"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0810",
    "brand": "SKF",
    "manufacturer_designation": "HK 0810",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 12,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 3.69,
    "static_load_kN": 4.05,
    "fatigue_load_limit_kN": 0.44,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 3,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 0810 denotes a 8×12×10 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. The designation HK 0810 encodes geometry only — there is no bore code to decode, since the 8 mm Fw is printed directly in the first digits and the cup width 10 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the HK 0810 like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 3.69/4.05 kN ratings are SKF catalogue values for this exact execution (HK 0810); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 3.69/4.05 kN ratings and 3 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the HK 0810 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 0810 have?",
        "a": "A HK 0810 measures 8 mm bore/Fw × 12 mm outside diameter × 10 mm width (0.315 × 0.472 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.69 kN, static C0 4.05 kN, fatigue limit Pu 0.44 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 3 g."
      },
      {
        "q": "What does HK 0810 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 8 mm, the last two the width 10 mm, the shell OD 12 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 0810 need a hardened and ground shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0810",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0810",
      "HK 0810"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0812-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 0812.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 12,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 2.7,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.285,
    "max_rpm": 13000,
    "limiting_speed_rpm": 13000,
    "weight_g": 3.3,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 0812.2RS is the standard caged drawn cup execution for a 8 mm shaft: ISO 3245 boundary dimensions (8×12×12 mm), open at both ends so the shaft can be pushed through, and rated 2.7 kN dynamic. In HK 0812, Fw = 8 mm names the shaft that becomes the inner raceway and B = 12 mm the cup width; the shell outside diameter 12 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 2.7 kN C against the open bearing of the same code. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. The 3.3 g catalogue mass and 2.0 mm radial section ((12−8)/2) frame a rating of about 0.34 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the HK 0812.2RS like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: HK 0812.2RS shares its 8×12×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 2.7/2.75 kN ratings and 3.3 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 0812.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 0812.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 0812.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 8 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0812.2RS?",
        "a": "A HK 0812.2RS measures 8 mm bore/Fw × 12 mm outside diameter × 12 mm width (0.315 × 0.472 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.7 kN, static C0 2.75 kN, fatigue limit Pu 0.285 kN, limiting speed 13,000 r/min, mass about 3.3 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0812",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0812-2RS",
      "HK 0812.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0908",
    "brand": "SKF",
    "manufacturer_designation": "HK 0908",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 13,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 3.52,
    "static_load_kN": 3.9,
    "fatigue_load_limit_kN": 0.415,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 3,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 0908 denotes a 9×13×8 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. SKF's HK numbering puts the shaft size first: 09 → Fw 9 mm (the ground, hardened journal), 08 → width 8 mm, with the 13 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. The 3 g catalogue mass and 2.0 mm radial section ((13−9)/2) frame a rating of about 0.39 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 13 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 3.52/3.9 kN ratings and 3 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 0908?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 9 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 0908?",
        "a": "A HK 0908 measures 9 mm bore/Fw × 13 mm outside diameter × 8 mm width (0.354 × 0.512 × 0.315 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.52 kN, static C0 3.9 kN, fatigue limit Pu 0.415 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 3 g."
      },
      {
        "q": "How is the HK 0908 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 9 mm, the last two the width 8 mm, the shell OD 13 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 0908 run on an unhardened shaft?",
        "a": "No. In this execution the 9 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0908",
      "HK 0908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0910",
    "brand": "SKF",
    "manufacturer_designation": "HK 0910",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 13,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 4.13,
    "static_load_kN": 4.8,
    "fatigue_load_limit_kN": 0.53,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 4,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 9 mm shaft in a thin housing wall, SKF catalogue execution HK 0910 offers a 10 mm wide, 13 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. Reading the code: HK marks the open-end drawn cup series, the first two digits (09) give the 9 mm under-roller diameter Fw, the last two (10) the 10 mm width; the 13 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. The 4 g catalogue mass and 2.0 mm radial section ((13−9)/2) frame a rating of about 0.46 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 13 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 18,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 9 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 4.13/4.8 kN ratings and 4 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the HK 0910 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 0910 have?",
        "a": "A HK 0910 measures 9 mm bore/Fw × 13 mm outside diameter × 10 mm width (0.354 × 0.512 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.13 kN, static C0 4.8 kN, fatigue limit Pu 0.53 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 4 g."
      },
      {
        "q": "What does HK 0910 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 9 mm, the last two the width 10 mm, the shell OD 13 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 0910 need a hardened and ground shaft?",
        "a": "No. In this execution the 9 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0910",
      "HK 0910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK0912",
    "brand": "SKF",
    "manufacturer_designation": "HK 0912",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 13,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 5.12,
    "static_load_kN": 6.4,
    "fatigue_load_limit_kN": 0.72,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 4.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 0912 gives the smallest radial section of any caged needle bearing with its own outer ring: 9 mm Fw, 13 mm OD and 12 mm width, the shell pressed directly into the housing bore. The designation HK 0912 encodes geometry only — there is no bore code to decode, since the 9 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. The 4.6 g catalogue mass and 2.0 mm radial section ((13−9)/2) frame a rating of about 0.57 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 13 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 0912 shares its 9×13×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 5.12/6.4 kN ratings and 4.6 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 0912 need a hardened and ground shaft?",
        "a": "No. In this execution the 9 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 0912?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 0912 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 0912 have?",
        "a": "A HK 0912 measures 9 mm bore/Fw × 13 mm outside diameter × 12 mm width (0.354 × 0.512 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.12 kN, static C0 6.4 kN, fatigue limit Pu 0.72 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 4.6 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK0912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK0912",
      "HK 0912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1010",
    "brand": "SKF",
    "manufacturer_designation": "HK 1010",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 14,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 4.29,
    "static_load_kN": 5.3,
    "fatigue_load_limit_kN": 0.57,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 4.1,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 1010 gives the smallest radial section of any caged needle bearing with its own outer ring: 10 mm Fw, 14 mm OD and 10 mm width, the shell pressed directly into the housing bore. In HK 1010, Fw = 10 mm names the shaft that becomes the inner raceway and B = 10 mm the cup width; the shell outside diameter 14 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Catalogue mass 4.1 g at 10×14×10 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 14 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 10 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 4.29/5.3 kN ratings are SKF catalogue values for this exact execution (HK 1010); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 4.29/5.3 kN ratings and 4.1 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 1010 run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1010 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1010?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 10 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1010?",
        "a": "A HK 1010 measures 10 mm bore/Fw × 14 mm outside diameter × 10 mm width (0.394 × 0.551 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.29 kN, static C0 5.3 kN, fatigue limit Pu 0.57 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 4.1 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1010",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1010",
      "HK 1010"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1012",
    "brand": "SKF",
    "manufacturer_designation": "HK 1012",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 14,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 5.39,
    "static_load_kN": 6.95,
    "fatigue_load_limit_kN": 0.78,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 4.8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 1012 for housings where machining an outer-ring pocket is uneconomical: the 14 mm shell broached from sheet steel press-fits into a plain bore and runs a 10 mm hardened shaft. SKF's HK numbering puts the shaft size first: 10 → Fw 10 mm (the ground, hardened journal), 12 → width 12 mm, with the 14 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Catalogue mass 4.8 g at 10×14×12 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 14 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 1012 shares its 10×14×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 18,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 5.39/6.95 kN ratings and 4.8 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the HK 1012?",
        "a": "A HK 1012 measures 10 mm bore/Fw × 14 mm outside diameter × 12 mm width (0.394 × 0.551 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.39 kN, static C0 6.95 kN, fatigue limit Pu 0.78 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 4.8 g."
      },
      {
        "q": "How is the HK 1012 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 10 mm, the last two the width 12 mm, the shell OD 14 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1012 run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1012 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1012",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1012",
      "HK 1012"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1014-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 1014.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 14,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 4.29,
    "static_load_kN": 5.3,
    "fatigue_load_limit_kN": 0.57,
    "max_rpm": 12000,
    "limiting_speed_rpm": 12000,
    "weight_g": 4.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 1014.2RS for housings where machining an outer-ring pocket is uneconomical: the 14 mm shell broached from sheet steel press-fits into a plain bore and runs a 10 mm hardened shaft. In HK 1014, Fw = 10 mm names the shaft that becomes the inner raceway and B = 14 mm the cup width; the shell outside diameter 14 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 4.29 kN C against the open bearing of the same code. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Catalogue mass 4.6 g at 10×14×14 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 14 mm section.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 14 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 10 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 4.29/5.3 kN ratings are SKF catalogue values for this exact execution (HK 1014.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 4.29/5.3 kN ratings and 4.6 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 1014.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 10 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1014.2RS?",
        "a": "A HK 1014.2RS measures 10 mm bore/Fw × 14 mm outside diameter × 14 mm width (0.394 × 0.551 × 0.551 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.29 kN, static C0 5.3 kN, fatigue limit Pu 0.57 kN, limiting speed 12,000 r/min, mass about 4.6 g."
      },
      {
        "q": "How is the HK 1014.2RS designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 10 mm, the last two the width 14 mm, the shell OD 14 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1014.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1014",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1014-2RS",
      "HK 1014.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1015",
    "brand": "SKF",
    "manufacturer_designation": "HK 1015",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 14,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.6,
    "static_load_kN": 9,
    "fatigue_load_limit_kN": 1.02,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 10 mm shaft in a thin housing wall, SKF catalogue execution HK 1015 offers a 15 mm wide, 14 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 1015 encodes geometry only — there is no bore code to decode, since the 10 mm Fw is printed directly in the first digits and the cup width 15 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Catalogue mass 6 g at 10×14×15 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 14 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 6.6/9 kN ratings are SKF catalogue values for this exact execution (HK 1015); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 6.6/9 kN ratings and 6 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 1015 need a hardened and ground shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 1015?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 1015 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 1015 have?",
        "a": "A HK 1015 measures 10 mm bore/Fw × 14 mm outside diameter × 15 mm width (0.394 × 0.551 × 0.591 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 6.6 kN, static C0 9 kN, fatigue limit Pu 1.02 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 6 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1015",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1015",
      "HK 1015"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1210",
    "brand": "SKF",
    "manufacturer_designation": "HK 1210",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 16,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 4.84,
    "static_load_kN": 6.4,
    "fatigue_load_limit_kN": 0.71,
    "max_rpm": 18000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 18000,
    "weight_g": 4.6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 1210 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 12 for the 12 mm under-roller diameter and 10 for the 10 mm width. SKF's HK numbering puts the shaft size first: 12 → Fw 12 mm (the ground, hardened journal), 10 → width 10 mm, with the 16 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 16 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 1210 shares its 12×16×10 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 16,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 4.84/6.4 kN ratings and 4.6 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the HK 1210 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1210?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 12 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1210?",
        "a": "A HK 1210 measures 12 mm bore/Fw × 16 mm outside diameter × 10 mm width (0.472 × 0.63 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.84 kN, static C0 6.4 kN, fatigue limit Pu 0.71 kN, limiting speed 18,000 r/min, reference speed 16,000 r/min, mass about 4.6 g."
      },
      {
        "q": "How is the HK 1210 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 12 mm, the last two the width 10 mm, the shell OD 16 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1210",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1210",
      "HK 1210"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1212",
    "brand": "SKF",
    "manufacturer_designation": "HK 1212",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 18,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.27,
    "static_load_kN": 7.35,
    "fatigue_load_limit_kN": 0.85,
    "max_rpm": 18000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 18000,
    "weight_g": 9.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 12 mm shaft in a thin housing wall, SKF catalogue execution HK 1212 offers a 12 mm wide, 18 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. In HK 1212, Fw = 12 mm names the shaft that becomes the inner raceway and B = 12 mm the cup width; the shell outside diameter 18 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 6.27/7.35 kN ratings and 9.5 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the HK 1212 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 12 mm, the last two the width 12 mm, the shell OD 18 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1212 run on an unhardened shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1212 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1212?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 12 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1212",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1212",
      "HK 1212"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1216-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 1216.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 18,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.27,
    "static_load_kN": 7.35,
    "fatigue_load_limit_kN": 0.85,
    "max_rpm": 10000,
    "limiting_speed_rpm": 10000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 1216.2RS is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 18 mm outside diameter carrying a caged needle roller set for a 12 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. In HK 1216, Fw = 12 mm names the shaft that becomes the inner raceway and B = 16 mm the cup width; the shell outside diameter 18 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 6.27 kN C against the open bearing of the same code. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Selection arithmetic: C 6.27 kN against C0 7.35 kN gives a C0/C ratio of 1.17, and the 0.85 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 18 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 6.27/7.35 kN ratings and 11 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the HK 1216.2RS?",
        "a": "A HK 1216.2RS measures 12 mm bore/Fw × 18 mm outside diameter × 16 mm width (0.472 × 0.709 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 6.27 kN, static C0 7.35 kN, fatigue limit Pu 0.85 kN, limiting speed 10,000 r/min, mass about 11 g."
      },
      {
        "q": "How is the HK 1216.2RS designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 12 mm, the last two the width 16 mm, the shell OD 18 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1216.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1216.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1216",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1216-2RS",
      "HK 1216.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1312",
    "brand": "SKF",
    "manufacturer_designation": "HK 1312",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 13,
    "D_mm": 19,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.6,
    "static_load_kN": 8,
    "fatigue_load_limit_kN": 0.915,
    "max_rpm": 17000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 17000,
    "weight_g": 10.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 1312 for housings where machining an outer-ring pocket is uneconomical: the 19 mm shell broached from sheet steel press-fits into a plain bore and runs a 13 mm hardened shaft. SKF's HK numbering puts the shaft size first: 13 → Fw 13 mm (the ground, hardened journal), 12 → width 12 mm, with the 19 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. The 10.5 g catalogue mass and 3.0 mm radial section ((19−13)/2) frame a rating of about 0.51 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 13 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 13 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 6.6/8 kN ratings are SKF catalogue values for this exact execution (HK 1312); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 6.6/8 kN ratings and 10.5 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the HK 1312 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 13 mm, the last two the width 12 mm, the shell OD 19 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1312 run on an unhardened shaft?",
        "a": "No. In this execution the 13 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1312 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1312?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 13 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1312",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1312",
      "HK 1312"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1412",
    "brand": "SKF",
    "manufacturer_designation": "HK 1412",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 20,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.82,
    "static_load_kN": 8.65,
    "fatigue_load_limit_kN": 0.98,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 10.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 1412 is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 20 mm outside diameter carrying a caged needle roller set for a 14 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. Reading the code: HK marks the open-end drawn cup series, the first two digits (14) give the 14 mm under-roller diameter Fw, the last two (12) the 12 mm width; the 20 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Speed planning separates the two ceilings: 15,000 r/min thermal reference and 17,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 14 mm seat. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 20 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 14 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 6.82/8.65 kN ratings and 10.5 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does HK 1412 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 14 mm, the last two the width 12 mm, the shell OD 20 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 1412 need a hardened and ground shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 1412?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 1412 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1412",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1412",
      "HK 1412"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1512",
    "brand": "SKF",
    "manufacturer_designation": "HK 1512",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 21,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.65,
    "static_load_kN": 9.5,
    "fatigue_load_limit_kN": 1.08,
    "max_rpm": 16000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 16000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 1512 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 15 for the 15 mm under-roller diameter and 12 for the 12 mm width. In HK 1512, Fw = 15 mm names the shaft that becomes the inner raceway and B = 12 mm the cup width; the shell outside diameter 21 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Selection arithmetic: C 7.65 kN against C0 9.5 kN gives a C0/C ratio of 1.24, and the 1.08 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 1512 shares its 15×21×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 7.65/9.5 kN ratings and 11 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the HK 1512 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 15 mm, the last two the width 12 mm, the shell OD 21 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1512 run on an unhardened shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1512 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1512?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1512",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1512",
      "HK 1512"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1516",
    "brand": "SKF",
    "manufacturer_designation": "HK 1516",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 21,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.1,
    "static_load_kN": 14.6,
    "fatigue_load_limit_kN": 1.7,
    "max_rpm": 16000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 16000,
    "weight_g": 15,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 1516 gives the smallest radial section of any caged needle bearing with its own outer ring: 15 mm Fw, 21 mm OD and 16 mm width, the shell pressed directly into the housing bore. In HK 1516, Fw = 15 mm names the shaft that becomes the inner raceway and B = 16 mm the cup width; the shell outside diameter 21 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Selection arithmetic: C 10.1 kN against C0 14.6 kN gives a C0/C ratio of 1.45, and the 1.7 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 10.1/14.6 kN ratings are SKF catalogue values for this exact execution (HK 1516); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 10.1/14.6 kN ratings and 15 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 1516 run on an unhardened shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1516 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1516?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1516?",
        "a": "A HK 1516 measures 15 mm bore/Fw × 21 mm outside diameter × 16 mm width (0.591 × 0.827 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 10.1 kN, static C0 14.6 kN, fatigue limit Pu 1.7 kN, limiting speed 16,000 r/min, reference speed 15,000 r/min, mass about 15 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1516",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1516",
      "HK 1516"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1522",
    "brand": "SKF",
    "manufacturer_designation": "HK 1522",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 21,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13,
    "static_load_kN": 20,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 16000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 16000,
    "weight_g": 20,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 1522 denotes a 15×21×22 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. The designation HK 1522 encodes geometry only — there is no bore code to decode, since the 15 mm Fw is printed directly in the first digits and the cup width 22 mm in the last two. Double-row execution: two rows of needle rollers share the 15 mm Fw seat in one cup — double the capacity of the single-row HK at the same 21×22 mm envelope. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Selection arithmetic: C 13 kN against C0 20 kN gives a C0/C ratio of 1.54, and the 2.28 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 22 mm section.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 13/20 kN ratings and 20 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 1522?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 1522 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 1522 have?",
        "a": "A HK 1522 measures 15 mm bore/Fw × 21 mm outside diameter × 22 mm width (0.591 × 0.827 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13 kN, static C0 20 kN, fatigue limit Pu 2.28 kN, limiting speed 16,000 r/min, reference speed 15,000 r/min, mass about 20 g."
      },
      {
        "q": "What does HK 1522 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 15 mm, the last two the width 22 mm, the shell OD 21 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1522",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1522",
      "HK 1522"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1612",
    "brand": "SKF",
    "manufacturer_designation": "HK 1612",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 22,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.37,
    "static_load_kN": 9.8,
    "fatigue_load_limit_kN": 1.12,
    "max_rpm": 16000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 16000,
    "weight_g": 12,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 1612 gives the smallest radial section of any caged needle bearing with its own outer ring: 16 mm Fw, 22 mm OD and 12 mm width, the shell pressed directly into the housing bore. The designation HK 1612 encodes geometry only — there is no bore code to decode, since the 16 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Selection arithmetic: C 7.37 kN against C0 9.8 kN gives a C0/C ratio of 1.33, and the 1.12 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 1612 shares its 16×22×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 7.37/9.8 kN ratings and 12 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 1612 need a hardened and ground shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 1612?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 1612 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 1612 have?",
        "a": "A HK 1612 measures 16 mm bore/Fw × 22 mm outside diameter × 12 mm width (0.63 × 0.866 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.37 kN, static C0 9.8 kN, fatigue limit Pu 1.12 kN, limiting speed 16,000 r/min, reference speed 14,000 r/min, mass about 12 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1612",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1612",
      "HK 1612"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1616",
    "brand": "SKF",
    "manufacturer_designation": "HK 1616",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 22,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 15.6,
    "fatigue_load_limit_kN": 1.8,
    "max_rpm": 16000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 16000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 1616 is the standard caged drawn cup execution for a 16 mm shaft: ISO 3245 boundary dimensions (16×22×16 mm), open at both ends so the shaft can be pushed through, and rated 10.5 kN dynamic. The designation HK 1616 encodes geometry only — there is no bore code to decode, since the 16 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Selection arithmetic: C 10.5 kN against C0 15.6 kN gives a C0/C ratio of 1.49, and the 1.8 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 14,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 16 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 10.5/15.6 kN ratings and 16 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 1616?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 1616 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 1616 have?",
        "a": "A HK 1616 measures 16 mm bore/Fw × 22 mm outside diameter × 16 mm width (0.63 × 0.866 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 10.5 kN, static C0 15.6 kN, fatigue limit Pu 1.8 kN, limiting speed 16,000 r/min, reference speed 14,000 r/min, mass about 16 g."
      },
      {
        "q": "What does HK 1616 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 16 mm, the last two the width 16 mm, the shell OD 22 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1616",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1616",
      "HK 1616"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1620-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 1620.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 22,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 15.6,
    "fatigue_load_limit_kN": 1.8,
    "max_rpm": 9000,
    "limiting_speed_rpm": 9000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 1620.2RS is the standard caged drawn cup execution for a 16 mm shaft: ISO 3245 boundary dimensions (16×22×20 mm), open at both ends so the shaft can be pushed through, and rated 10.5 kN dynamic. SKF's HK numbering puts the shaft size first: 16 → Fw 16 mm (the ground, hardened journal), 20 → width 20 mm, with the 22 mm shell OD from the ISO 3245 dimension table. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 10.5 kN C against the open bearing of the same code. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. The 18 g catalogue mass and 3.0 mm radial section ((22−16)/2) frame a rating of about 0.66 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 1620.2RS shares its 16×22×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 10.5/15.6 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 1620.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1620.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1620.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 16 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1620.2RS?",
        "a": "A HK 1620.2RS measures 16 mm bore/Fw × 22 mm outside diameter × 20 mm width (0.63 × 0.866 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 10.5 kN, static C0 15.6 kN, fatigue limit Pu 1.8 kN, limiting speed 9,000 r/min, mass about 18 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1620",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1620-2RS",
      "HK 1620.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1622",
    "brand": "SKF",
    "manufacturer_designation": "HK 1622",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 22,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 19.6,
    "fatigue_load_limit_kN": 2.24,
    "max_rpm": 16000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 16000,
    "weight_g": 24,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 16 mm shaft in a thin housing wall, SKF catalogue execution HK 1622 offers a 22 mm wide, 22 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. SKF's HK numbering puts the shaft size first: 16 → Fw 16 mm (the ground, hardened journal), 22 → width 22 mm, with the 22 mm shell OD from the ISO 3245 dimension table. Double-row execution: two rows of needle rollers share the 16 mm Fw seat in one cup — double the capacity of the single-row HK at the same 22×22 mm envelope. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Selection arithmetic: C 12.8 kN against C0 19.6 kN gives a C0/C ratio of 1.53, and the 2.24 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 1622 shares its 16×22×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 14,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 12.8/19.6 kN ratings and 24 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 1622?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 16 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1622?",
        "a": "A HK 1622 measures 16 mm bore/Fw × 22 mm outside diameter × 22 mm width (0.63 × 0.866 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.8 kN, static C0 19.6 kN, fatigue limit Pu 2.24 kN, limiting speed 16,000 r/min, reference speed 14,000 r/min, mass about 24 g."
      },
      {
        "q": "How is the HK 1622 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 16 mm, the last two the width 22 mm, the shell OD 22 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 1622 run on an unhardened shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1622",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1622",
      "HK 1622"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1712",
    "brand": "SKF",
    "manufacturer_designation": "HK 1712",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 23,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.65,
    "static_load_kN": 10.6,
    "fatigue_load_limit_kN": 1.2,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 13,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 1712 is the standard caged drawn cup execution for a 17 mm shaft: ISO 3245 boundary dimensions (17×23×12 mm), open at both ends so the shaft can be pushed through, and rated 7.65 kN dynamic. Reading the code: HK marks the open-end drawn cup series, the first two digits (17) give the 17 mm under-roller diameter Fw, the last two (12) the 12 mm width; the 23 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 23 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 7.65/10.6 kN ratings are SKF catalogue values for this exact execution (HK 1712); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 7.65/10.6 kN ratings and 13 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 620); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 1712 need a hardened and ground shaft?",
        "a": "No. In this execution the 17 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 1712?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 1712 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 1712 have?",
        "a": "A HK 1712 measures 17 mm bore/Fw × 23 mm outside diameter × 12 mm width (0.669 × 0.906 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.65 kN, static C0 10.6 kN, fatigue limit Pu 1.2 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 13 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1712",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1712",
      "HK 1712"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1812",
    "brand": "SKF",
    "manufacturer_designation": "HK 1812",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 18,
    "D_mm": 24,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.92,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 1.27,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 13,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 1812 denotes a 18×24×12 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. In HK 1812, Fw = 18 mm names the shaft that becomes the inner raceway and B = 12 mm the cup width; the shell outside diameter 24 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. For life calculation, the 7.92/11.2 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 18 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 18 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 7.92/11.2 kN ratings are SKF catalogue values for this exact execution (HK 1812); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 7.92/11.2 kN ratings and 13 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 1812 run on an unhardened shaft?",
        "a": "No. In this execution the 18 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 1812 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1812?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 18 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1812?",
        "a": "A HK 1812 measures 18 mm bore/Fw × 24 mm outside diameter × 12 mm width (0.709 × 0.945 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.92 kN, static C0 11.2 kN, fatigue limit Pu 1.27 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 13 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1812",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1812",
      "HK 1812"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1816-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 1816.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 18,
    "D_mm": 24,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.92,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 1.27,
    "max_rpm": 8500,
    "limiting_speed_rpm": 8500,
    "weight_g": 15,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 18 mm shaft in a thin housing wall, SKF catalogue execution HK 1816.2RS offers a 16 mm wide, 24 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 1816.2RS encodes geometry only — there is no bore code to decode, since the 18 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 7.92 kN C against the open bearing of the same code. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 8,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 18 mm seat. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 18 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 1816.2RS shares its 18×24×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 7.92/11.2 kN ratings and 15 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 1816.2RS have?",
        "a": "A HK 1816.2RS measures 18 mm bore/Fw × 24 mm outside diameter × 16 mm width (0.709 × 0.945 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.92 kN, static C0 11.2 kN, fatigue limit Pu 1.27 kN, limiting speed 8,500 r/min, mass about 15 g."
      },
      {
        "q": "What does HK 1816.2RS mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 18 mm, the last two the width 16 mm, the shell OD 24 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 1816.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 18 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 1816.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1816",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 18×24×16 mm envelope, but catalogue C/C0 differ between the executions (7.92/11.2 vs 11.2/17.6 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1816-2RS",
      "HK 1816.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK1816",
    "brand": "SKF",
    "manufacturer_designation": "HK 1816",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 18,
    "D_mm": 24,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.2,
    "static_load_kN": 17.6,
    "fatigue_load_limit_kN": 2.04,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 18 mm shaft in a thin housing wall, SKF catalogue execution HK 1816 offers a 16 mm wide, 24 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. In HK 1816, Fw = 18 mm names the shaft that becomes the inner raceway and B = 16 mm the cup width; the shell outside diameter 24 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. For life calculation, the 11.2/17.6 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 18 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 11.2/17.6 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the HK 1816 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 1816?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 18 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 1816?",
        "a": "A HK 1816 measures 18 mm bore/Fw × 24 mm outside diameter × 16 mm width (0.709 × 0.945 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.2 kN, static C0 17.6 kN, fatigue limit Pu 2.04 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 18 g."
      },
      {
        "q": "How is the HK 1816 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 18 mm, the last two the width 16 mm, the shell OD 24 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK1816-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 18×24×16 mm envelope, but catalogue C/C0 differ between the executions (11.2/17.6 vs 7.92/11.2 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK1816",
      "HK 1816"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2010",
    "brand": "SKF",
    "manufacturer_designation": "HK 2010",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.16,
    "static_load_kN": 8.5,
    "fatigue_load_limit_kN": 0.93,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 12,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 2010 gives the smallest radial section of any caged needle bearing with its own outer ring: 20 mm Fw, 26 mm OD and 10 mm width, the shell pressed directly into the housing bore. In HK 2010, Fw = 20 mm names the shaft that becomes the inner raceway and B = 10 mm the cup width; the shell outside diameter 26 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 12 g at 20×26×10 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 6.16/8.5 kN ratings and 12 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 2010 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2010 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 2010?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 2010?",
        "a": "A HK 2010 measures 20 mm bore/Fw × 26 mm outside diameter × 10 mm width (0.787 × 1.024 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 6.16 kN, static C0 8.5 kN, fatigue limit Pu 0.93 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 12 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2010",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2010",
      "HK 2010"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2012",
    "brand": "SKF",
    "manufacturer_designation": "HK 2012",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.42,
    "static_load_kN": 12.5,
    "fatigue_load_limit_kN": 1.4,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 14,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 2012 for housings where machining an outer-ring pocket is uneconomical: the 26 mm shell broached from sheet steel press-fits into a plain bore and runs a 20 mm hardened shaft. SKF's HK numbering puts the shaft size first: 20 → Fw 20 mm (the ground, hardened journal), 12 → width 12 mm, with the 26 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 14 g at 20×26×12 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 20 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 8.42/12.5 kN ratings are SKF catalogue values for this exact execution (HK 2012); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 8.42/12.5 kN ratings and 14 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the HK 2012?",
        "a": "A HK 2012 measures 20 mm bore/Fw × 26 mm outside diameter × 12 mm width (0.787 × 1.024 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.42 kN, static C0 12.5 kN, fatigue limit Pu 1.4 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 14 g."
      },
      {
        "q": "How is the HK 2012 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 20 mm, the last two the width 12 mm, the shell OD 26 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 2012 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2012 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2012",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2012",
      "HK 2012"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2016-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2016.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.42,
    "static_load_kN": 12.5,
    "fatigue_load_limit_kN": 1.4,
    "max_rpm": 8000,
    "limiting_speed_rpm": 8000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 2016.2RS is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 26 mm outside diameter carrying a caged needle roller set for a 20 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. The designation HK 2016.2RS encodes geometry only — there is no bore code to decode, since the 20 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 8.42 kN C against the open bearing of the same code. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 2016.2RS shares its 20×26×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 8.42/12.5 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 2016.2RS have?",
        "a": "A HK 2016.2RS measures 20 mm bore/Fw × 26 mm outside diameter × 16 mm width (0.787 × 1.024 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.42 kN, static C0 12.5 kN, fatigue limit Pu 1.4 kN, limiting speed 8,000 r/min, mass about 18 g."
      },
      {
        "q": "What does HK 2016.2RS mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 20 mm, the last two the width 16 mm, the shell OD 26 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2016.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2016.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2016",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×26×16 mm envelope, but catalogue C/C0 differ between the executions (8.42/12.5 vs 12.3/20.4 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2016-2RS",
      "HK 2016.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2016",
    "brand": "SKF",
    "manufacturer_designation": "HK 2016",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.3,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 2.36,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 2016 is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 26 mm outside diameter carrying a caged needle roller set for a 20 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. SKF's HK numbering puts the shaft size first: 20 → Fw 20 mm (the ground, hardened journal), 16 → width 16 mm, with the 26 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 19 g at 20×26×16 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 12.3/20.4 kN ratings and 19 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the HK 2016 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 20 mm, the last two the width 16 mm, the shell OD 26 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 2016 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2016 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 2016?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2016-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×26×16 mm envelope, but catalogue C/C0 differ between the executions (12.3/20.4 vs 8.42/12.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2016",
      "HK 2016"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2020-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2020.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.3,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 2.36,
    "max_rpm": 8000,
    "limiting_speed_rpm": 8000,
    "weight_g": 23,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 20 mm shaft in a thin housing wall, SKF catalogue execution HK 2020.2RS offers a 20 mm wide, 26 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 2020.2RS encodes geometry only — there is no bore code to decode, since the 20 mm Fw is printed directly in the first digits and the cup width 20 mm in the last two. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 12.3 kN C against the open bearing of the same code. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 12.3/20.4 kN ratings are SKF catalogue values for this exact execution (HK 2020.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 12.3/20.4 kN ratings and 23 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 2020.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2020.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2020.2RS sealed?",
        "a": "Yes — this is the 2RS execution with rubber contact seals on both cup faces and a factory grease fill, sealed for life at the 20 mm seat. The open HK execution of the same code relies on the housing for sealing."
      },
      {
        "q": "Which dimensions does the HK 2020.2RS have?",
        "a": "A HK 2020.2RS measures 20 mm bore/Fw × 26 mm outside diameter × 20 mm width (0.787 × 1.024 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.3 kN, static C0 20.4 kN, fatigue limit Pu 2.36 kN, limiting speed 8,000 r/min, mass about 23 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2020",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×26×20 mm envelope, but catalogue C/C0 differ between the executions (12.3/20.4 vs 15.1/26.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2020-2RS",
      "HK 2020.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2020",
    "brand": "SKF",
    "manufacturer_designation": "HK 2020",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 26.5,
    "fatigue_load_limit_kN": 3.15,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 24,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 20 mm shaft in a thin housing wall, SKF catalogue execution HK 2020 offers a 20 mm wide, 26 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 2020 encodes geometry only — there is no bore code to decode, since the 20 mm Fw is printed directly in the first digits and the cup width 20 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 24 g at 20×26×20 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 2020 shares its 20×26×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 15.1/26.5 kN ratings and 24 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the HK 2020 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 2020 have?",
        "a": "A HK 2020 measures 20 mm bore/Fw × 26 mm outside diameter × 20 mm width (0.787 × 1.024 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 26.5 kN, fatigue limit Pu 3.15 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 24 g."
      },
      {
        "q": "What does HK 2020 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 20 mm, the last two the width 20 mm, the shell OD 26 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2020 need a hardened and ground shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2020-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×26×20 mm envelope, but catalogue C/C0 differ between the executions (15.1/26.5 vs 12.3/20.4 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2020",
      "HK 2020"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2030",
    "brand": "SKF",
    "manufacturer_designation": "HK 2030",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 26,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 20.9,
    "static_load_kN": 40.5,
    "fatigue_load_limit_kN": 4.75,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 35,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 2030 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 20 for the 20 mm under-roller diameter and 30 for the 30 mm width. SKF's HK numbering puts the shaft size first: 20 → Fw 20 mm (the ground, hardened journal), 30 → width 30 mm, with the 26 mm shell OD from the ISO 3245 dimension table. Double-row execution: two rows of needle rollers share the 20 mm Fw seat in one cup — double the capacity of the single-row HK at the same 26×30 mm envelope. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 35 g at 20×26×30 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 2030 shares its 20×26×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 12,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 20.9/40.5 kN ratings and 35 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the HK 2030 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 20 mm, the last two the width 30 mm, the shell OD 26 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 2030 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2030 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 2030?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2030",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2030",
      "HK 2030"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2210",
    "brand": "SKF",
    "manufacturer_designation": "HK 2210",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 28,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.21,
    "static_load_kN": 10.6,
    "fatigue_load_limit_kN": 1.2,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 13,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 2210 denotes a 22×28×10 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. Reading the code: HK marks the open-end drawn cup series, the first two digits (22) give the 22 mm under-roller diameter Fw, the last two (10) the 10 mm width; the 28 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. For life calculation, the 7.21/10.6 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 7.21/10.6 kN ratings and 13 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 2210?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2210 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 2210 have?",
        "a": "A HK 2210 measures 22 mm bore/Fw × 28 mm outside diameter × 10 mm width (0.866 × 1.102 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.21 kN, static C0 10.6 kN, fatigue limit Pu 1.2 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 13 g."
      },
      {
        "q": "What does HK 2210 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 22 mm, the last two the width 10 mm, the shell OD 28 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2210",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2210",
      "HK 2210"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2212",
    "brand": "SKF",
    "manufacturer_designation": "HK 2212",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 28,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.8,
    "static_load_kN": 13.7,
    "fatigue_load_limit_kN": 1.56,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 15,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 2212 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 22 for the 22 mm under-roller diameter and 12 for the 12 mm width. The designation HK 2212 encodes geometry only — there is no bore code to decode, since the 22 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. For life calculation, the 8.8/13.7 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 2212 shares its 22×28×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 8.8/13.7 kN ratings and 15 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does HK 2212 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 22 mm, the last two the width 12 mm, the shell OD 28 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2212 need a hardened and ground shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2212?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2212 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2212",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2212",
      "HK 2212"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2216-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2216.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 28,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.8,
    "static_load_kN": 13.7,
    "fatigue_load_limit_kN": 1.56,
    "max_rpm": 7500,
    "limiting_speed_rpm": 7500,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 2216.2RS denotes a 22×28×16 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. Reading the code: HK marks the open-end drawn cup series, the first two digits (22) give the 22 mm under-roller diameter Fw, the last two (16) the 16 mm width; the 28 mm OD follows the ISO 3245 plan. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 8.8 kN C against the open bearing of the same code. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 8.8/13.7 kN ratings are SKF catalogue values for this exact execution (HK 2216.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 8.8/13.7 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 2216.2RS have?",
        "a": "A HK 2216.2RS measures 22 mm bore/Fw × 28 mm outside diameter × 16 mm width (0.866 × 1.102 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.8 kN, static C0 13.7 kN, fatigue limit Pu 1.56 kN, limiting speed 7,500 r/min, mass about 18 g."
      },
      {
        "q": "What does HK 2216.2RS mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 22 mm, the last two the width 16 mm, the shell OD 28 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2216.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2216.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 22×28×16 mm envelope, but catalogue C/C0 differ between the executions (8.8/13.7 vs 13/22.4 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2216-2RS",
      "HK 2216.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2216",
    "brand": "SKF",
    "manufacturer_designation": "HK 2216",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 28,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13,
    "static_load_kN": 22.4,
    "fatigue_load_limit_kN": 2.6,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 2216 gives the smallest radial section of any caged needle bearing with its own outer ring: 22 mm Fw, 28 mm OD and 16 mm width, the shell pressed directly into the housing bore. The designation HK 2216 encodes geometry only — there is no bore code to decode, since the 22 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. For life calculation, the 13/22.4 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 13/22.4 kN ratings and 21 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 2216 need a hardened and ground shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2216?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2216 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 2216 have?",
        "a": "A HK 2216 measures 22 mm bore/Fw × 28 mm outside diameter × 16 mm width (0.866 × 1.102 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13 kN, static C0 22.4 kN, fatigue limit Pu 2.6 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 21 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2216-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 22×28×16 mm envelope, but catalogue C/C0 differ between the executions (13/22.4 vs 8.8/13.7 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2216",
      "HK 2216"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2220-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2220.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 28,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13,
    "static_load_kN": 22.4,
    "fatigue_load_limit_kN": 2.6,
    "max_rpm": 7500,
    "limiting_speed_rpm": 7500,
    "weight_g": 23,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 2220.2RS gives the smallest radial section of any caged needle bearing with its own outer ring: 22 mm Fw, 28 mm OD and 20 mm width, the shell pressed directly into the housing bore. SKF's HK numbering puts the shaft size first: 22 → Fw 22 mm (the ground, hardened journal), 20 → width 20 mm, with the 28 mm shell OD from the ISO 3245 dimension table. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 13 kN C against the open bearing of the same code. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Catalogue mass 23 g at 22×28×20 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 13/22.4 kN ratings are SKF catalogue values for this exact execution (HK 2220.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 13/22.4 kN ratings and 23 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 2220.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2220.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 2220.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 22 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 2220.2RS?",
        "a": "A HK 2220.2RS measures 22 mm bore/Fw × 28 mm outside diameter × 20 mm width (0.866 × 1.102 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13 kN, static C0 22.4 kN, fatigue limit Pu 2.6 kN, limiting speed 7,500 r/min, mass about 23 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2220",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 22×28×20 mm envelope, but catalogue C/C0 differ between the executions (13/22.4 vs 15.7/29 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2220-2RS",
      "HK 2220.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2220",
    "brand": "SKF",
    "manufacturer_designation": "HK 2220",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 28,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.7,
    "static_load_kN": 29,
    "fatigue_load_limit_kN": 3.45,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 2220 is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 28 mm outside diameter carrying a caged needle roller set for a 22 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. In HK 2220, Fw = 22 mm names the shaft that becomes the inner raceway and B = 20 mm the cup width; the shell outside diameter 28 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. For life calculation, the 15.7/29 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 15.7/29 kN ratings are SKF catalogue values for this exact execution (HK 2220); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 15.7/29 kN ratings and 26 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the HK 2220?",
        "a": "A HK 2220 measures 22 mm bore/Fw × 28 mm outside diameter × 20 mm width (0.866 × 1.102 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.7 kN, static C0 29 kN, fatigue limit Pu 3.45 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 26 g."
      },
      {
        "q": "How is the HK 2220 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 22 mm, the last two the width 20 mm, the shell OD 28 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 2220 run on an unhardened shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2220 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2220-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 22×28×20 mm envelope, but catalogue C/C0 differ between the executions (15.7/29 vs 13/22.4 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2220",
      "HK 2220"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2512",
    "brand": "SKF",
    "manufacturer_designation": "HK 2512",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.76,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 20,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 2512 denotes a 25×32×12 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. The designation HK 2512 encodes geometry only — there is no bore code to decode, since the 25 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 20 g at 25×32×12 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 9,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 10.5/15.3 kN ratings and 20 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does HK 2512 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 25 mm, the last two the width 12 mm, the shell OD 32 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2512 need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2512?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2512 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2512",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2512",
      "HK 2512"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2516-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2516.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.76,
    "max_rpm": 6700,
    "limiting_speed_rpm": 6700,
    "weight_g": 27,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 2516.2RS in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 25 for the 25 mm under-roller diameter and 16 for the 16 mm width. The designation HK 2516.2RS encodes geometry only — there is no bore code to decode, since the 25 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 10.5 kN C against the open bearing of the same code. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 27 g at 25×32×16 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 10.5/15.3 kN ratings and 27 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 2516.2RS have?",
        "a": "A HK 2516.2RS measures 25 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.984 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 10.5 kN, static C0 15.3 kN, fatigue limit Pu 1.76 kN, limiting speed 6,700 r/min, mass about 27 g."
      },
      {
        "q": "What does HK 2516.2RS mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 25 mm, the last two the width 16 mm, the shell OD 32 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2516.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2516.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2516",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×32×16 mm envelope, but catalogue C/C0 differ between the executions (10.5/15.3 vs 15.1/24 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2516-2RS",
      "HK 2516.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2516",
    "brand": "SKF",
    "manufacturer_designation": "HK 2516",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 24,
    "fatigue_load_limit_kN": 2.85,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 25 mm shaft in a thin housing wall, SKF catalogue execution HK 2516 offers a 16 mm wide, 32 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 2516 encodes geometry only — there is no bore code to decode, since the 25 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 25 g at 25×32×16 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 15.1/24 kN ratings are SKF catalogue values for this exact execution (HK 2516); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 15.1/24 kN ratings and 25 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 2516 need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2516?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2516 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 2516 have?",
        "a": "A HK 2516 measures 25 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.984 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 24 kN, fatigue limit Pu 2.85 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 25 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2516-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×32×16 mm envelope, but catalogue C/C0 differ between the executions (15.1/24 vs 10.5/15.3 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2516",
      "HK 2516"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2520-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2520.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 24,
    "fatigue_load_limit_kN": 2.85,
    "max_rpm": 6700,
    "limiting_speed_rpm": 6700,
    "weight_g": 31,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 2520.2RS is the standard caged drawn cup execution for a 25 mm shaft: ISO 3245 boundary dimensions (25×32×20 mm), open at both ends so the shaft can be pushed through, and rated 15.1 kN dynamic. In HK 2520, Fw = 25 mm names the shaft that becomes the inner raceway and B = 20 mm the cup width; the shell outside diameter 32 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 15.1 kN C against the open bearing of the same code. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Selection arithmetic: C 15.1 kN against C0 24 kN gives a C0/C ratio of 1.59, and the 2.85 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: HK 2520.2RS shares its 25×32×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 15.1/24 kN ratings and 31 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 2520.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 2520.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 2520.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 2520.2RS?",
        "a": "A HK 2520.2RS measures 25 mm bore/Fw × 32 mm outside diameter × 20 mm width (0.984 × 1.26 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 24 kN, fatigue limit Pu 2.85 kN, limiting speed 6,700 r/min, mass about 31 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2520",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 25×32×20 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2520-2RS",
      "HK 2520.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2526",
    "brand": "SKF",
    "manufacturer_designation": "HK 2526",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.5,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 44,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 2526 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 25 for the 25 mm under-roller diameter and 26 for the 26 mm width. SKF's HK numbering puts the shaft size first: 25 → Fw 25 mm (the ground, hardened journal), 26 → width 26 mm, with the 32 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 44 g at 25×32×26 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 24.2/45 kN ratings and 44 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 2526?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 2526?",
        "a": "A HK 2526 measures 25 mm bore/Fw × 32 mm outside diameter × 26 mm width (0.984 × 1.26 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.2 kN, static C0 45 kN, fatigue limit Pu 5.5 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 44 g."
      },
      {
        "q": "How is the HK 2526 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 25 mm, the last two the width 26 mm, the shell OD 32 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 2526 run on an unhardened shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2526",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2526",
      "HK 2526"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2530-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2530.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.5,
    "max_rpm": 6700,
    "limiting_speed_rpm": 6700,
    "weight_g": 47,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 2530.2RS denotes a 25×32×30 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. In HK 2530, Fw = 25 mm names the shaft that becomes the inner raceway and B = 30 mm the cup width; the shell outside diameter 32 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 24.2 kN C against the open bearing of the same code. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. For life calculation, the 24.2/45 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 30 mm section.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 24.2/45 kN ratings are SKF catalogue values for this exact execution (HK 2530.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 24.2/45 kN ratings and 47 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 2530.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 2530.2RS?",
        "a": "A HK 2530.2RS measures 25 mm bore/Fw × 32 mm outside diameter × 30 mm width (0.984 × 1.26 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.2 kN, static C0 45 kN, fatigue limit Pu 5.5 kN, limiting speed 6,700 r/min, mass about 47 g."
      },
      {
        "q": "How is the HK 2530.2RS designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 25 mm, the last two the width 30 mm, the shell OD 32 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 2530.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2530",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2530-2RS",
      "HK 2530.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2538",
    "brand": "SKF",
    "manufacturer_designation": "HK 2538",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 32,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 33,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 64,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 2538 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 25 for the 25 mm under-roller diameter and 38 for the 38 mm width. The designation HK 2538 encodes geometry only — there is no bore code to decode, since the 25 mm Fw is printed directly in the first digits and the cup width 38 mm in the last two. Double-row execution: two rows of needle rollers share the 25 mm Fw seat in one cup — double the capacity of the single-row HK at the same 32×38 mm envelope. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Catalogue mass 64 g at 25×32×38 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 38 mm section.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 33/65.5 kN ratings are SKF catalogue values for this exact execution (HK 2538); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 33/65.5 kN ratings and 64 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the HK 2538 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 2538 have?",
        "a": "A HK 2538 measures 25 mm bore/Fw × 32 mm outside diameter × 38 mm width (0.984 × 1.26 × 1.496 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 33 kN, static C0 65.5 kN, fatigue limit Pu 8 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 64 g."
      },
      {
        "q": "What does HK 2538 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 25 mm, the last two the width 38 mm, the shell OD 32 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 2538 need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2538",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2538",
      "HK 2538"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2816",
    "brand": "SKF",
    "manufacturer_designation": "HK 2816",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 35,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.7,
    "static_load_kN": 26.5,
    "fatigue_load_limit_kN": 3.15,
    "max_rpm": 9500,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 9500,
    "weight_g": 26.5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 28 mm shaft in a thin housing wall, SKF catalogue execution HK 2816 offers a 16 mm wide, 35 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 2816 encodes geometry only — there is no bore code to decode, since the 28 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. The 26.5 g catalogue mass and 3.5 mm radial section ((35−28)/2) frame a rating of about 0.56 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 2816 shares its 28×35×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 15.7/26.5 kN ratings and 26.5 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 2816?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2816 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 2816 have?",
        "a": "A HK 2816 measures 28 mm bore/Fw × 35 mm outside diameter × 16 mm width (1.102 × 1.378 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.7 kN, static C0 26.5 kN, fatigue limit Pu 3.15 kN, limiting speed 9,500 r/min, reference speed 9,000 r/min, mass about 26.5 g."
      },
      {
        "q": "What does HK 2816 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 28 mm, the last two the width 16 mm, the shell OD 35 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2816",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2816",
      "HK 2816"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK2820-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 2820.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 35,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.7,
    "static_load_kN": 26.5,
    "fatigue_load_limit_kN": 3.15,
    "max_rpm": 6300,
    "limiting_speed_rpm": 6300,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 2820.2RS is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 35 mm outside diameter carrying a caged needle roller set for a 28 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. Reading the code: HK marks the open-end drawn cup series, the first two digits (28) give the 28 mm under-roller diameter Fw, the last two (20) the 20 mm width; the 35 mm OD follows the ISO 3245 plan. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 15.7 kN C against the open bearing of the same code. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Selection arithmetic: C 15.7 kN against C0 26.5 kN gives a C0/C ratio of 1.69, and the 3.15 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 15.7/26.5 kN ratings are SKF catalogue values for this exact execution (HK 2820.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 15.7/26.5 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 2820.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 28 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 2820.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 2820.2RS sealed?",
        "a": "Yes — this is the 2RS execution with rubber contact seals on both cup faces and a factory grease fill, sealed for life at the 28 mm seat. The open HK execution of the same code relies on the housing for sealing."
      },
      {
        "q": "Which dimensions does the HK 2820.2RS have?",
        "a": "A HK 2820.2RS measures 28 mm bore/Fw × 35 mm outside diameter × 20 mm width (1.102 × 1.378 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.7 kN, static C0 26.5 kN, fatigue limit Pu 3.15 kN, limiting speed 6,300 r/min, mass about 34 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK2820",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 28×35×20 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK2820-2RS",
      "HK 2820.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3012",
    "brand": "SKF",
    "manufacturer_designation": "HK 3012",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.7,
    "static_load_kN": 18.3,
    "fatigue_load_limit_kN": 2.12,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 23,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 3012 for housings where machining an outer-ring pocket is uneconomical: the 37 mm shell broached from sheet steel press-fits into a plain bore and runs a 30 mm hardened shaft. Reading the code: HK marks the open-end drawn cup series, the first two digits (30) give the 30 mm under-roller diameter Fw, the last two (12) the 12 mm width; the 37 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 12 mm section.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 11.7/18.3 kN ratings are SKF catalogue values for this exact execution (HK 3012); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 11.7/18.3 kN ratings and 23 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 3012 have?",
        "a": "A HK 3012 measures 30 mm bore/Fw × 37 mm outside diameter × 12 mm width (1.181 × 1.457 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.7 kN, static C0 18.3 kN, fatigue limit Pu 2.12 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 23 g."
      },
      {
        "q": "What does HK 3012 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 12 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 3012 need a hardened and ground shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 3012?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3012",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3012",
      "HK 3012"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3016-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 3016.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 37,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.7,
    "static_load_kN": 18.3,
    "fatigue_load_limit_kN": 2.12,
    "max_rpm": 5600,
    "limiting_speed_rpm": 5600,
    "weight_g": 31,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 3016.2RS is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 37 mm outside diameter carrying a caged needle roller set for a 30 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. In HK 3016, Fw = 30 mm names the shaft that becomes the inner raceway and B = 16 mm the cup width; the shell outside diameter 37 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 11.7 kN C against the open bearing of the same code. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. The 31 g catalogue mass and 3.5 mm radial section ((37−30)/2) frame a rating of about 0.39 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 16 mm section.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 11.7/18.3 kN ratings and 31 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the HK 3016.2RS?",
        "a": "A HK 3016.2RS measures 30 mm bore/Fw × 37 mm outside diameter × 16 mm width (1.181 × 1.457 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.7 kN, static C0 18.3 kN, fatigue limit Pu 2.12 kN, limiting speed 5,600 r/min, mass about 31 g."
      },
      {
        "q": "How is the HK 3016.2RS designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 16 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 3016.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 3016.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3016",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×37×16 mm envelope, but catalogue C/C0 differ between the executions (11.7/18.3 vs 16.5/29 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3016-2RS",
      "HK 3016.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3016",
    "brand": "SKF",
    "manufacturer_designation": "HK 3016",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 37,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 29,
    "fatigue_load_limit_kN": 3.4,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 31,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 3016 is an open-end drawn cup needle roller bearing to ISO 3245: a hardened, thin-walled shell of 37 mm outside diameter carrying a caged needle roller set for a 30 mm shaft, listed by SKF in SKF catalogue PUB BU/P1 17000. Reading the code: HK marks the open-end drawn cup series, the first two digits (30) give the 30 mm under-roller diameter Fw, the last two (16) the 16 mm width; the 37 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 16 mm section.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 3016 shares its 30×37×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 16.5/29 kN ratings and 31 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does HK 3016 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 16 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 3016 need a hardened and ground shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 3016?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 3016 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3016-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×37×16 mm envelope, but catalogue C/C0 differ between the executions (16.5/29 vs 11.7/18.3 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3016",
      "HK 3016"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3020",
    "brand": "SKF",
    "manufacturer_designation": "HK 3020",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 37,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 20.9,
    "static_load_kN": 40,
    "fatigue_load_limit_kN": 4.75,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 38,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 30 mm shaft in a thin housing wall, SKF catalogue execution HK 3020 offers a 20 mm wide, 37 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. SKF's HK numbering puts the shaft size first: 30 → Fw 30 mm (the ground, hardened journal), 20 → width 20 mm, with the 37 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: HK 3020 shares its 30×37×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 20.9/40 kN ratings and 38 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 3020?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 3020?",
        "a": "A HK 3020 measures 30 mm bore/Fw × 37 mm outside diameter × 20 mm width (1.181 × 1.457 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 20.9 kN, static C0 40 kN, fatigue limit Pu 4.75 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 38 g."
      },
      {
        "q": "How is the HK 3020 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 20 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 3020 run on an unhardened shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3020",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3020",
      "HK 3020"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3026",
    "brand": "SKF",
    "manufacturer_designation": "HK 3026",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 37,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 51,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 3026 is the standard caged drawn cup execution for a 30 mm shaft: ISO 3245 boundary dimensions (30×37×26 mm), open at both ends so the shaft can be pushed through, and rated 27 kN dynamic. In HK 3026, Fw = 30 mm names the shaft that becomes the inner raceway and B = 26 mm the cup width; the shell outside diameter 37 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: HK 3026 shares its 30×37×26 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 27/54 kN ratings and 51 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the HK 3026 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 3026?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 3026?",
        "a": "A HK 3026 measures 30 mm bore/Fw × 37 mm outside diameter × 26 mm width (1.181 × 1.457 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27 kN, static C0 54 kN, fatigue limit Pu 6.55 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 51 g."
      },
      {
        "q": "How is the HK 3026 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 26 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3026",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3026",
      "HK 3026"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3038",
    "brand": "SKF",
    "manufacturer_designation": "HK 3038",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 37,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 35.8,
    "static_load_kN": 80,
    "fatigue_load_limit_kN": 9.5,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 76,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 3038 is the standard caged drawn cup execution for a 30 mm shaft: ISO 3245 boundary dimensions (30×37×38 mm), open at both ends so the shaft can be pushed through, and rated 35.8 kN dynamic. Reading the code: HK marks the open-end drawn cup series, the first two digits (30) give the 30 mm under-roller diameter Fw, the last two (38) the 38 mm width; the 37 mm OD follows the ISO 3245 plan. Double-row execution: two rows of needle rollers share the 30 mm Fw seat in one cup — double the capacity of the single-row HK at the same 37×38 mm envelope. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 3038 shares its 30×37×38 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 35.8/80 kN ratings and 76 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 622); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a HK 3038?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 3038 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 3038 have?",
        "a": "A HK 3038 measures 30 mm bore/Fw × 37 mm outside diameter × 38 mm width (1.181 × 1.457 × 1.496 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 35.8 kN, static C0 80 kN, fatigue limit Pu 9.5 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 76 g."
      },
      {
        "q": "What does HK 3038 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 30 mm, the last two the width 38 mm, the shell OD 37 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3038",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3038",
      "HK 3038"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3512",
    "brand": "SKF",
    "manufacturer_designation": "HK 3512",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 42,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.5,
    "static_load_kN": 21.6,
    "fatigue_load_limit_kN": 2.45,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 27,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 3512 denotes a 35×42×12 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. The designation HK 3512 encodes geometry only — there is no bore code to decode, since the 35 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Catalogue mass 27 g at 35×42×12 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 12.5/21.6 kN ratings are SKF catalogue values for this exact execution (HK 3512); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 12.5/21.6 kN ratings and 27 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does HK 3512 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 35 mm, the last two the width 12 mm, the shell OD 42 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 3512 need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 3512?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 3512 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3512",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3512",
      "HK 3512"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3516",
    "brand": "SKF",
    "manufacturer_designation": "HK 3516",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 42,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.9,
    "static_load_kN": 34,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 35 mm shaft in a thin housing wall, SKF catalogue execution HK 3516 offers a 16 mm wide, 42 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 3516 encodes geometry only — there is no bore code to decode, since the 35 mm Fw is printed directly in the first digits and the cup width 16 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Catalogue mass 36 g at 35×42×16 mm makes this one of the highest capacity-per-gram choices in the drawn cup needle roller bearings, open end; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 3516 shares its 35×42×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 17.9/34 kN ratings and 36 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 3516 need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 3516?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 3516 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 3516 have?",
        "a": "A HK 3516 measures 35 mm bore/Fw × 42 mm outside diameter × 16 mm width (1.378 × 1.654 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 17.9 kN, static C0 34 kN, fatigue limit Pu 4 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 36 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3516",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3516",
      "HK 3516"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK3520-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 3520.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.9,
    "static_load_kN": 34,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 5000,
    "limiting_speed_rpm": 5000,
    "weight_g": 41,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 3520.2RS is the standard caged drawn cup execution for a 35 mm shaft: ISO 3245 boundary dimensions (35×42×20 mm), open at both ends so the shaft can be pushed through, and rated 17.9 kN dynamic. Reading the code: HK marks the open-end drawn cup series, the first two digits (35) give the 35 mm under-roller diameter Fw, the last two (20) the 20 mm width; the 42 mm OD follows the ISO 3245 plan. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 17.9 kN C against the open bearing of the same code. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 3520.2RS shares its 35×42×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 17.9/34 kN ratings and 41 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 3520.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 3520.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 3520.2RS sealed?",
        "a": "Yes — this is the 2RS execution with rubber contact seals on both cup faces and a factory grease fill, sealed for life at the 35 mm seat. The open HK execution of the same code relies on the housing for sealing."
      },
      {
        "q": "Which dimensions does the HK 3520.2RS have?",
        "a": "A HK 3520.2RS measures 35 mm bore/Fw × 42 mm outside diameter × 20 mm width (1.378 × 1.654 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 17.9 kN, static C0 34 kN, fatigue limit Pu 4 kN, limiting speed 5,000 r/min, mass about 41 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK3520",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 35×42×20 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK3520-2RS",
      "HK 3520.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4012",
    "brand": "SKF",
    "manufacturer_designation": "HK 4012",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 47,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.4,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 2.8,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 4012 gives the smallest radial section of any caged needle bearing with its own outer ring: 40 mm Fw, 47 mm OD and 12 mm width, the shell pressed directly into the housing bore. Reading the code: HK marks the open-end drawn cup series, the first two digits (40) give the 40 mm under-roller diameter Fw, the last two (12) the 12 mm width; the 47 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: HK 4012 shares its 40×47×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 13.4/24.5 kN ratings and 30 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 4012 have?",
        "a": "A HK 4012 measures 40 mm bore/Fw × 47 mm outside diameter × 12 mm width (1.575 × 1.85 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.4 kN, static C0 24.5 kN, fatigue limit Pu 2.8 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 30 g."
      },
      {
        "q": "What does HK 4012 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 40 mm, the last two the width 12 mm, the shell OD 47 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 4012 need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 4012?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4012",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4012",
      "HK 4012"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4016-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 4016.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 47,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 27.5,
    "fatigue_load_limit_kN": 3.15,
    "max_rpm": 4500,
    "limiting_speed_rpm": 4500,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 4016.2RS denotes a 40×47×16 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. Reading the code: HK marks the open-end drawn cup series, the first two digits (40) give the 40 mm under-roller diameter Fw, the last two (16) the 16 mm width; the 47 mm OD follows the ISO 3245 plan. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 14.5 kN C against the open bearing of the same code. Caged HK bearings space the rollers for lower friction than full complement HK types; the cage is not a seal — 2RS executions are the sealed members of the family. Selection arithmetic: C 14.5 kN against C0 27.5 kN gives a C0/C ratio of 1.90, and the 3.15 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 14.5/27.5 kN ratings are SKF catalogue values for this exact execution (HK 4016.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 14.5/27.5 kN ratings and 37 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 4016.2RS have?",
        "a": "A HK 4016.2RS measures 40 mm bore/Fw × 47 mm outside diameter × 16 mm width (1.575 × 1.85 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 14.5 kN, static C0 27.5 kN, fatigue limit Pu 3.15 kN, limiting speed 4,500 r/min, mass about 37 g."
      },
      {
        "q": "What does HK 4016.2RS mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 40 mm, the last two the width 16 mm, the shell OD 47 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 4016.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 4016.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4016",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×47×16 mm envelope, but catalogue C/C0 differ between the executions (14.5/27.5 vs 19/39 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4016-2RS",
      "HK 4016.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4016",
    "brand": "SKF",
    "manufacturer_designation": "HK 4016",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 47,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.55,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 39,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 4016 is the standard caged drawn cup execution for a 40 mm shaft: ISO 3245 boundary dimensions (40×47×16 mm), open at both ends so the shaft can be pushed through, and rated 19 kN dynamic. Reading the code: HK marks the open-end drawn cup series, the first two digits (40) give the 40 mm under-roller diameter Fw, the last two (16) the 16 mm width; the 47 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 6,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 19/39 kN ratings and 39 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does HK 4016 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 40 mm, the last two the width 16 mm, the shell OD 47 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 4016 need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 4016?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 4016 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4016-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×47×16 mm envelope, but catalogue C/C0 differ between the executions (19/39 vs 14.5/27.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4016",
      "HK 4016"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4020-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 4020.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 47,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.55,
    "max_rpm": 4500,
    "limiting_speed_rpm": 4500,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "The drawn cup bearing HK 4020.2RS gives the smallest radial section of any caged needle bearing with its own outer ring: 40 mm Fw, 47 mm OD and 20 mm width, the shell pressed directly into the housing bore. SKF's HK numbering puts the shaft size first: 40 → Fw 40 mm (the ground, hardened journal), 20 → width 20 mm, with the 47 mm shell OD from the ISO 3245 dimension table. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 19 kN C against the open bearing of the same code. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 4,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 40 mm seat. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 19/39 kN ratings are SKF catalogue values for this exact execution (HK 4020.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 19/39 kN ratings and 48 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 4020.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 4020.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 4020.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 4020.2RS?",
        "a": "A HK 4020.2RS measures 40 mm bore/Fw × 47 mm outside diameter × 20 mm width (1.575 × 1.85 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 39 kN, fatigue limit Pu 4.55 kN, limiting speed 4,500 r/min, mass about 48 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4020",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×47×20 mm envelope, but catalogue C/C0 differ between the executions (19/39 vs 24.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4020-2RS",
      "HK 4020.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4020",
    "brand": "SKF",
    "manufacturer_designation": "HK 4020",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 47,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 53,
    "fatigue_load_limit_kN": 6.4,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 54,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 4020 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 40 for the 40 mm under-roller diameter and 20 for the 20 mm width. Reading the code: HK marks the open-end drawn cup series, the first two digits (40) give the 40 mm under-roller diameter Fw, the last two (20) the 20 mm width; the 47 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. For life calculation, the 24.2/53 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 6,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 24.2/53 kN ratings and 54 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the HK 4020 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 4020 have?",
        "a": "A HK 4020 measures 40 mm bore/Fw × 47 mm outside diameter × 20 mm width (1.575 × 1.85 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.2 kN, static C0 53 kN, fatigue limit Pu 6.4 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 54 g."
      },
      {
        "q": "What does HK 4020 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 40 mm, the last two the width 20 mm, the shell OD 47 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 4020 need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4020-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×47×20 mm envelope, but catalogue C/C0 differ between the executions (24.2/53 vs 19/39 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4020",
      "HK 4020"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4512",
    "brand": "SKF",
    "manufacturer_designation": "HK 4512",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 52,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 27.5,
    "fatigue_load_limit_kN": 3.2,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 4512 denotes a 45×52×12 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. SKF's HK numbering puts the shaft size first: 45 → Fw 45 mm (the ground, hardened journal), 12 → width 12 mm, with the 52 mm shell OD from the ISO 3245 dimension table. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 12 mm section.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 14.2/27.5 kN ratings and 33 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the HK 4512 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 45 mm, the last two the width 12 mm, the shell OD 52 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 4512 run on an unhardened shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 4512 be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 4512?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4512",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4512",
      "HK 4512"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK4520-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 4520.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 52,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 20.5,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.1,
    "max_rpm": 4000,
    "limiting_speed_rpm": 4000,
    "weight_g": 54,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "HK 4520.2RS is the standard caged drawn cup execution for a 45 mm shaft: ISO 3245 boundary dimensions (45×52×20 mm), open at both ends so the shaft can be pushed through, and rated 20.5 kN dynamic. SKF's HK numbering puts the shaft size first: 45 → Fw 45 mm (the ground, hardened journal), 20 → width 20 mm, with the 52 mm shell OD from the ISO 3245 dimension table. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 20.5 kN C against the open bearing of the same code. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. The 54 g catalogue mass and 3.5 mm radial section ((52−45)/2) frame a rating of about 0.46 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 20.5/43 kN ratings and 54 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the HK 4520.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the HK 4520.2RS be mounted?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "What limits the service life of a HK 4520.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 4520.2RS?",
        "a": "A HK 4520.2RS measures 45 mm bore/Fw × 52 mm outside diameter × 20 mm width (1.772 × 2.047 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 20.5 kN, static C0 43 kN, fatigue limit Pu 5.1 kN, limiting speed 4,000 r/min, mass about 54 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK4520",
        "equiv_brand": "NTN",
        "level": "partial",
        "note": "Same 45×52×20 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK4520-2RS",
      "HK 4520.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK5024-2RS",
    "brand": "SKF",
    "manufacturer_designation": "HK 5024.2RS",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 58,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 29.2,
    "static_load_kN": 63,
    "fatigue_load_limit_kN": 7.8,
    "max_rpm": 3600,
    "limiting_speed_rpm": 3600,
    "weight_g": 81,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 5024.2RS denotes a 50×58×24 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. Reading the code: HK marks the open-end drawn cup series, the first two digits (50) give the 50 mm under-roller diameter Fw, the last two (24) the 24 mm width; the 58 mm OD follows the ISO 3245 plan. Sealed 2RS execution: rubber contact seals on both cup faces, factory grease fill, and the slightly lower ratings of a sealed drawn cup — 29.2 kN C against the open bearing of the same code. Drawn cups exist open (basic HK), sealed (2RS, with contact seals and grease fill) and with polymer TN cage; each is a separate order number with its own ratings, not a field conversion. Selection arithmetic: C 29.2 kN against C0 63 kN gives a C0/C ratio of 2.16, and the 7.8 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives",
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 29.2/63 kN ratings and 81 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 5024.2RS have?",
        "a": "A HK 5024.2RS measures 50 mm bore/Fw × 58 mm outside diameter × 24 mm width (1.969 × 2.283 × 0.945 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 29.2 kN, static C0 63 kN, fatigue limit Pu 7.8 kN, limiting speed 3,600 r/min, mass about 81 g."
      },
      {
        "q": "What does HK 5024.2RS mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 50 mm, the last two the width 24 mm, the shell OD 58 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 5024.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 5024.2RS?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK5024",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK5024-2RS",
      "HK 5024.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK5520",
    "brand": "SKF",
    "manufacturer_designation": "HK 5520",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 63,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 30.3,
    "static_load_kN": 67,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 74,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "SKF supplies HK 5520 for housings where machining an outer-ring pocket is uneconomical: the 63 mm shell broached from sheet steel press-fits into a plain bore and runs a 55 mm hardened shaft. The designation HK 5520 encodes geometry only — there is no bore code to decode, since the 55 mm Fw is printed directly in the first digits and the cup width 20 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 30.3/67 kN ratings are SKF catalogue values for this exact execution (HK 5520); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 30.3/67 kN ratings and 74 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 5520 have?",
        "a": "A HK 5520 measures 55 mm bore/Fw × 63 mm outside diameter × 20 mm width (2.165 × 2.48 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 30.3 kN, static C0 67 kN, fatigue limit Pu 8.3 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 74 g."
      },
      {
        "q": "What does HK 5520 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 55 mm, the last two the width 20 mm, the shell OD 63 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 5520 need a hardened and ground shaft?",
        "a": "No. In this execution the 55 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 5520?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK5520",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK5520",
      "HK 5520"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK5528",
    "brand": "SKF",
    "manufacturer_designation": "HK 5528",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 63,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 41.8,
    "static_load_kN": 104,
    "fatigue_load_limit_kN": 12.9,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 105,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "Ordering number HK 5528 in SKF catalogue PUB BU/P1 17000 is an open-end HK drawn cup needle roller bearing: nominal code 55 for the 55 mm under-roller diameter and 28 for the 28 mm width. The designation HK 5528 encodes geometry only — there is no bore code to decode, since the 55 mm Fw is printed directly in the first digits and the cup width 28 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The shell itself is the outer ring: hardened sheet steel, closed at neither end (open type), so the shaft can pass through and lubricant can be fed axially along the journal. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 28 mm section.",
    "applications": [
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains",
      "steering column and pedal-box pivots in passenger cars",
      "idler gears and pulleys in small appliance drives"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 4,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 41.8/104 kN ratings and 105 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the HK 5528 need a hardened and ground shaft?",
        "a": "No. In this execution the 55 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 5528?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      },
      {
        "q": "Is the HK 5528 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 5528 have?",
        "a": "A HK 5528 measures 55 mm bore/Fw × 63 mm outside diameter × 28 mm width (2.165 × 2.48 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 41.8 kN, static C0 104 kN, fatigue limit Pu 12.9 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 105 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK5528",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK5528",
      "HK 5528"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK6012",
    "brand": "SKF",
    "manufacturer_designation": "HK 6012",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 68,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.6,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.8,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 49,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "For a 60 mm shaft in a thin housing wall, SKF catalogue execution HK 6012 offers a 12 mm wide, 68 mm diameter pressed shell with caged needle rollers — the classic minimal-section drawn cup solution. The designation HK 6012 encodes geometry only — there is no bore code to decode, since the 60 mm Fw is printed directly in the first digits and the cup width 12 mm in the last two. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. The 49 g catalogue mass and 4.0 mm radial section ((68−60)/2) frame a rating of about 0.29 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: press the cup in with a shouldered mandrel against the stamped end face only — through-the-rollers pressing brinells both raceways; the housing bore takes a firm press fit and the shaft slides in after.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 4,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 60 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 17.6/32 kN ratings and 49 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the HK 6012 have?",
        "a": "A HK 6012 measures 60 mm bore/Fw × 68 mm outside diameter × 12 mm width (2.362 × 2.677 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 17.6 kN, static C0 32 kN, fatigue limit Pu 3.8 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 49 g."
      },
      {
        "q": "What does HK 6012 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 60 mm, the last two the width 12 mm, the shell OD 68 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 6012 need a hardened and ground shaft?",
        "a": "No. In this execution the 60 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a HK 6012?",
        "a": "Press the cup in with a shouldered mandrel bearing on the stamped face, into a housing bore sized for a firm press fit; never hammer it or press through the rollers. Then slide the hardened shaft in. For 2RS executions the seals and grease are already in place — no additional sealing is needed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK6012",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK6012",
      "HK 6012"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK6020",
    "brand": "SKF",
    "manufacturer_designation": "HK 6020",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 68,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 75,
    "fatigue_load_limit_kN": 9.3,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 81,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 6020 denotes a 60×68×20 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. In HK 6020, Fw = 60 mm names the shaft that becomes the inner raceway and B = 20 mm the cup width; the shell outside diameter 68 mm is fixed by the boundary plan, so the housing bore needs only a press-fit tolerance. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. The 81 g catalogue mass and 4.0 mm radial section ((68−60)/2) frame a rating of about 0.53 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Open ends mean the housing must do the sealing; where that is impossible, the 2RS execution with its integrated seals and grease fill replaces sealing rings that would not fit the 20 mm section.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "drawn-cup shell distortion or splitting from a careless press-in without a seating mandrel",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 31.9/75 kN ratings and 81 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a HK 6020?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 60 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the HK 6020?",
        "a": "A HK 6020 measures 60 mm bore/Fw × 68 mm outside diameter × 20 mm width (2.362 × 2.677 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 75 kN, fatigue limit Pu 9.3 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 81 g."
      },
      {
        "q": "How is the HK 6020 designation read?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 60 mm, the last two the width 20 mm, the shell OD 68 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Can the HK 6020 run on an unhardened shaft?",
        "a": "No. In this execution the 60 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK6020",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK6020",
      "HK 6020"
    ],
    "locale_variants": {}
  },
  {
    "sku": "HK6032",
    "brand": "SKF",
    "manufacturer_designation": "HK 6032",
    "series": "HK-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 68,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 51.2,
    "static_load_kN": 137,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 136,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 3245",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, HK 6032 denotes a 60×68×32 mm drawn cup needle roller bearing with open ends — the shaft journal is the inner raceway, the pressed shell the outer, and the cage keeps the rollers parallel. Reading the code: HK marks the open-end drawn cup series, the first two digits (60) give the 60 mm under-roller diameter Fw, the last two (32) the 32 mm width; the 68 mm OD follows the ISO 3245 plan. Open caged execution: the standard HK drawn cup with steel cage, relubricable through the shaft where the housing allows. The suffix TN denotes the glass fibre reinforced PA66 cage; the 2RS execution adds rubber contact seals on both faces, retaining factory grease for life-lubricated pivots. The 136 g catalogue mass and 4.0 mm radial section ((68−60)/2) frame a rating of about 0.85 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. The shell is intentionally thin: seat it square with a slow press stroke, support the housing wall behind the bore, and stop the moment the cup face meets the shoulder — hammer blows split drawn cups.",
    "applications": [
      "spindle clusters of drilling and tapping units",
      "auto steering gear rack supports",
      "clutch release mechanisms and cable pulleys",
      "office equipment and power tool gear trains"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "fretting corrosion of the cup outside diameter in a soft or oversized housing bore",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 51.2/137 kN ratings are SKF catalogue values for this exact execution (HK 6032); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 51.2/137 kN ratings and 136 g mass are SKF catalogue values transcribed from ch. 7.2 of PUB BU/P1 17000 (PDF table page 624); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the HK 6032 sealed?",
        "a": "No — the open-end HK cup has no seals: the housing must keep contamination out and grease in. The 2RS execution of the same code adds both-side contact seals with a grease fill."
      },
      {
        "q": "Which dimensions does the HK 6032 have?",
        "a": "A HK 6032 measures 60 mm bore/Fw × 68 mm outside diameter × 32 mm width (2.362 × 2.677 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 51.2 kN, static C0 137 kN, fatigue limit Pu 17 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 136 g."
      },
      {
        "q": "What does HK 6032 mean in SKF part numbering?",
        "a": "HK = open-end drawn cup needle roller bearing (ISO 3245); the first two digits give Fw 60 mm, the last two the width 32 mm, the shell OD 68 mm follows the plan. 2RS adds both-side contact seals, TN the polymer cage."
      },
      {
        "q": "Does the HK 6032 need a hardened and ground shaft?",
        "a": "No. In this execution the 60 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "HK6032",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.2 drawn cup needle roller bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "HK6032",
      "HK 6032"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK5-10-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 5/10 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 10,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.29,
    "static_load_kN": 2,
    "fatigue_load_limit_kN": 0.212,
    "max_rpm": 40000,
    "reference_speed_rpm": 36000,
    "limiting_speed_rpm": 40000,
    "weight_g": 3.1,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 5/10 TN belongs to the machined-ring needle roller family: an outer ring turned and ground to 10 mm with two retaining flanges, a roller-and-cage set inside, and envelope 5×10×10 mm on a hardened 5 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 5 mm under-roller diameter and the 10 mm width, with the 10 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. For life calculation, the 2.29/2 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the NK 5/10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 2.29/2 kN ratings are SKF catalogue values for this exact execution (NK 5/10 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 2.29/2 kN ratings and 3.1 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 5/10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 5 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 5/10 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 5 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 5/10 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 5/10 TN have?",
        "a": "A NK 5/10 TN measures 5 mm bore/Fw × 10 mm outside diameter × 10 mm width (0.197 × 0.394 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.29 kN, static C0 2 kN, fatigue limit Pu 0.212 kN, limiting speed 40,000 r/min, reference speed 36,000 r/min, mass about 3.1 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK5-10-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 5×10×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK5-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK5",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK5-10-TN",
      "NK 5/10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK5-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 5/12 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 10,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.92,
    "static_load_kN": 2.7,
    "fatigue_load_limit_kN": 0.29,
    "max_rpm": 40000,
    "reference_speed_rpm": 36000,
    "limiting_speed_rpm": 40000,
    "weight_g": 3.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 5/12 TN: 5 mm Fw, 10 mm outside diameter, 12 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 5 mm Fw and 12 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 3.7 g catalogue mass and 2.5 mm radial section ((10−5)/2) frame a rating of about 0.58 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 10 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the NK 5/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Do not interchange envelope-identical needle families blindly: NK 5/12 TN shares its 5×10×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 36,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 2.92/2.7 kN ratings and 3.7 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 5/12 TN run on an unhardened shaft?",
        "a": "No. In this execution the 5 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 5/12 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 5 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 5/12 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 5 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 2.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 5/12 TN?",
        "a": "A NK 5/12 TN measures 5 mm bore/Fw × 10 mm outside diameter × 12 mm width (0.197 × 0.394 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.92 kN, static C0 2.7 kN, fatigue limit Pu 0.29 kN, limiting speed 40,000 r/min, reference speed 36,000 r/min, mass about 3.7 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK5-10-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK5-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 5×10×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK5",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK5-12-TN",
      "NK 5/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK6-10-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 6/10 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 12,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.55,
    "static_load_kN": 2.36,
    "fatigue_load_limit_kN": 0.25,
    "max_rpm": 38000,
    "reference_speed_rpm": 34000,
    "limiting_speed_rpm": 38000,
    "weight_g": 4.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 6/10 TN: 6 mm Fw, 12 mm outside diameter, 10 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 6 mm Fw and 10 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 2.55/2.36 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the NK 6/10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Hardness is load capacity: in families without an inner ring the 6 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 2.55/2.36 kN ratings are SKF catalogue values for this exact execution (NK 6/10 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 2.55/2.36 kN ratings and 4.7 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 6/10 TN run on an unhardened shaft?",
        "a": "No. In this execution the 6 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 6/10 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 6 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 6/10 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 6 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 6/10 TN?",
        "a": "A NK 6/10 TN measures 6 mm bore/Fw × 12 mm outside diameter × 10 mm width (0.236 × 0.472 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.55 kN, static C0 2.36 kN, fatigue limit Pu 0.25 kN, limiting speed 38,000 r/min, reference speed 34,000 r/min, mass about 4.7 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK6-10-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 6×12×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK6-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK6",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK6-10-TN",
      "NK 6/10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK6-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 6/12 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 12,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.3,
    "static_load_kN": 3.2,
    "fatigue_load_limit_kN": 0.345,
    "max_rpm": 38000,
    "reference_speed_rpm": 34000,
    "limiting_speed_rpm": 38000,
    "weight_g": 5.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 6/12 TN is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 6 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: NK gives the series and the numbers the boundary plan — 6 mm Fw for the shaft seat, 12 mm width; the 12 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 5.7 g catalogue mass and 3.0 mm radial section ((12−6)/2) frame a rating of about 0.55 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the NK 6/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 6/12 TN shares its 6×12×12 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 3.3/3.2 kN ratings and 5.7 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 6/12 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 6 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 6/12 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 6 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 6/12 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 6/12 TN have?",
        "a": "A NK 6/12 TN measures 6 mm bore/Fw × 12 mm outside diameter × 12 mm width (0.236 × 0.472 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.3 kN, static C0 3.2 kN, fatigue limit Pu 0.345 kN, limiting speed 38,000 r/min, reference speed 34,000 r/min, mass about 5.7 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK6-10-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK6-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 6×12×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK6",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK6-12-TN",
      "NK 6/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK7-10-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 7/10 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 14,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.81,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.29,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 6.8999999999999995,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 7/10 TN is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 7 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: NK gives the series and the numbers the boundary plan — 7 mm Fw for the shaft seat, 10 mm width; the 14 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 2.81/2.75 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the NK 7/10 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Reference and limiting speeds are different limits: the 32,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 7 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 2.81/2.75 kN ratings and 6.8999999999999995 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 7/10 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 7 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 7/10 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 7 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 7/10 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 7/10 TN have?",
        "a": "A NK 7/10 TN measures 7 mm bore/Fw × 14 mm outside diameter × 10 mm width (0.276 × 0.551 × 0.394 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 2.81 kN, static C0 2.75 kN, fatigue limit Pu 0.29 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 6.8999999999999995 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK7-10-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 7×14×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK7-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK7",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK7-10-TN",
      "NK 7/10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK7-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 7/12 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 14,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.58,
    "static_load_kN": 3.75,
    "fatigue_load_limit_kN": 0.415,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 8.200000000000001,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 7/12 TN in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 7 mm bore seat and 14 mm OD. The NK 7/12 TN code states Fw 7 and width 12 mm directly; because the family has no inner ring, the 7 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. The 8.200000000000001 g catalogue mass and 3.5 mm radial section ((14−7)/2) frame a rating of about 0.51 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the NK 7/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 3.58/3.75 kN ratings and 8.200000000000001 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 7/12 TN run on an unhardened shaft?",
        "a": "No. In this execution the 7 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 7/12 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 7 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 7/12 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 7 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 7/12 TN?",
        "a": "A NK 7/12 TN measures 7 mm bore/Fw × 14 mm outside diameter × 12 mm width (0.276 × 0.551 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.58 kN, static C0 3.75 kN, fatigue limit Pu 0.415 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 8.200000000000001 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK7-10-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK7-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 7×14×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK7",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK7-12-TN",
      "NK 7/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK8-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 8/12 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 15,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.8,
    "static_load_kN": 4.25,
    "fatigue_load_limit_kN": 0.465,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 8.7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 8/12 TN belongs to the machined-ring needle roller family: an outer ring turned and ground to 15 mm with two retaining flanges, a roller-and-cage set inside, and envelope 8×15×12 mm on a hardened 8 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 8 mm under-roller diameter and the 12 mm width, with the 15 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. The 8.7 g catalogue mass and 3.5 mm radial section ((15−8)/2) frame a rating of about 0.47 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the NK 8/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 3.8/4.25 kN ratings are SKF catalogue values for this exact execution (NK 8/12 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 3.8/4.25 kN ratings and 8.7 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 8/12 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 8/12 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 8 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 8/12 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 8/12 TN have?",
        "a": "A NK 8/12 TN measures 8 mm bore/Fw × 15 mm outside diameter × 12 mm width (0.315 × 0.591 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 3.8 kN, static C0 4.25 kN, fatigue limit Pu 0.465 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 8.7 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK8-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 8×15×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK8-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK8",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK8-12-TN",
      "NK 8/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK8-16-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 8/16 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 8,
    "D_mm": 15,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.01,
    "static_load_kN": 5.85,
    "fatigue_load_limit_kN": 0.67,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 12,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 8/16 TN: 8 mm Fw, 15 mm outside diameter, 16 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. Reading the designation: NK gives the series and the numbers the boundary plan — 8 mm Fw for the shaft seat, 16 mm width; the 15 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Catalogue mass 12 g at 8×15×16 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 15 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At Fw 8 mm the rolling elements are under two millimetres long — handle the NK 8/16 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 5.01/5.85 kN ratings are SKF catalogue values for this exact execution (NK 8/16 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 5.01/5.85 kN ratings and 12 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 8/16 TN mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 8 mm and width 16 mm, OD 15 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 8/16 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 8 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 8/16 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 8 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 8/16 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK8-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK8-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 8×15×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK8",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK8-16-TN",
      "NK 8/16 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK9-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 9/12 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 16,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.4,
    "static_load_kN": 5.2,
    "fatigue_load_limit_kN": 0.57,
    "max_rpm": 34000,
    "reference_speed_rpm": 30000,
    "limiting_speed_rpm": 34000,
    "weight_g": 10,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 9/12 TN designates a flanged, machined outer ring filled with needle rollers and a cage for a 9 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 9 mm under-roller diameter and the 12 mm width, with the 16 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 4.4/5.2 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 16 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 16 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 4.4/5.2 kN ratings are SKF catalogue values for this exact execution (NK 9/12 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 4.4/5.2 kN ratings and 10 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 9/12 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 9 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 9/12 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 9 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 9/12 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 9/12 TN have?",
        "a": "A NK 9/12 TN measures 9 mm bore/Fw × 16 mm outside diameter × 12 mm width (0.354 × 0.63 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.4 kN, static C0 5.2 kN, fatigue limit Pu 0.57 kN, limiting speed 34,000 r/min, reference speed 30,000 r/min, mass about 10 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK9-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 9×16×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK9-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK9",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK9-12-TN",
      "NK 9/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK9-16-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 9/16 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 16,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.72,
    "static_load_kN": 7.2,
    "fatigue_load_limit_kN": 0.815,
    "max_rpm": 34000,
    "reference_speed_rpm": 30000,
    "limiting_speed_rpm": 34000,
    "weight_g": 13,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 9/16 TN is a ribbed machined-ring needle roller bearing (no inner ring) sized 9×16×16 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 9 mm shaft journal completes the bearing. The NK 9/16 TN code states Fw 9 and width 16 mm directly; because the family has no inner ring, the 9 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Catalogue mass 13 g at 9×16×16 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 16 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 16 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 9 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 5.72/7.2 kN ratings are SKF catalogue values for this exact execution (NK 9/16 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 5.72/7.2 kN ratings and 13 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 9/16 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 9 mm and width 16 mm, OD 16 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 9/16 TN run on an unhardened shaft?",
        "a": "No. In this execution the 9 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 9/16 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 9 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 9/16 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 9 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK9-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK9-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 9×16×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK9",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK9-16-TN",
      "NK 9/16 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK10-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 10/12 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 17,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.57,
    "static_load_kN": 5.7,
    "fatigue_load_limit_kN": 0.63,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 10,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 10/12 TN belongs to the machined-ring needle roller family: an outer ring turned and ground to 17 mm with two retaining flanges, a roller-and-cage set inside, and envelope 10×17×12 mm on a hardened 10 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 10 mm Fw and 12 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 17 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 4.57/5.7 kN ratings and 10 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 10/12 TN?",
        "a": "A NK 10/12 TN measures 10 mm bore/Fw × 17 mm outside diameter × 12 mm width (0.394 × 0.669 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.57 kN, static C0 5.7 kN, fatigue limit Pu 0.63 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 10 g."
      },
      {
        "q": "How is the NK 10/12 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 10 mm and width 12 mm, OD 17 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 10/12 TN run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 10/12 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 10 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK10-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×17×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK10-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK10-12-TN",
      "NK 10/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK10-16-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 10/16 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 17,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.94,
    "static_load_kN": 8,
    "fatigue_load_limit_kN": 0.9,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 13,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 10/16 TN: 10 mm Fw, 17 mm outside diameter, 16 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The NK 10/16 TN code states Fw 10 and width 16 mm directly; because the family has no inner ring, the 10 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 13 g catalogue mass and 3.5 mm radial section ((17−10)/2) frame a rating of about 0.59 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 17 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 5.94/8 kN ratings and 13 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 10/16 TN?",
        "a": "A NK 10/16 TN measures 10 mm bore/Fw × 17 mm outside diameter × 16 mm width (0.394 × 0.669 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.94 kN, static C0 8 kN, fatigue limit Pu 0.9 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 13 g."
      },
      {
        "q": "How is the NK 10/16 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 10 mm and width 16 mm, OD 17 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 10/16 TN run on an unhardened shaft?",
        "a": "No. In this execution the 10 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 10/16 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 10 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK10-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK10-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×17×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK10-16-TN",
      "NK 10/16 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK12-12",
    "brand": "SKF",
    "manufacturer_designation": "NK 12/12",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 19,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.71,
    "static_load_kN": 8.15,
    "fatigue_load_limit_kN": 0.965,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 12,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 12/12 is a ribbed machined-ring needle roller bearing (no inner ring) sized 12×19×12 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 12 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 12 mm Fw for the shaft seat, 12 mm width; the 19 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 12 g at 12×19×12 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 26,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 6.71/8.15 kN ratings and 12 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 12/12 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 12 mm and width 12 mm, OD 19 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 12/12 need a hardened and ground shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 12/12?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 12 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 12/12 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK12-12-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×19×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK12-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK12",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK12-12",
      "NK 12/12"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK12-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 12/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 19,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12,
    "fatigue_load_limit_kN": 1.43,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 12/16 belongs to the machined-ring needle roller family: an outer ring turned and ground to 19 mm with two retaining flanges, a roller-and-cage set inside, and envelope 12×19×16 mm on a hardened 12 mm shaft. Reading the designation: NK gives the series and the numbers the boundary plan — 12 mm Fw for the shaft seat, 16 mm width; the 19 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 16 g at 12×19×16 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 9.13/12 kN ratings are SKF catalogue values for this exact execution (NK 12/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 9.13/12 kN ratings and 16 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 12/16 need a hardened and ground shaft?",
        "a": "No. In this execution the 12 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 12/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 12 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 12/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 12/16 have?",
        "a": "A NK 12/16 measures 12 mm bore/Fw × 19 mm outside diameter × 16 mm width (0.472 × 0.748 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12 kN, fatigue limit Pu 1.43 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 16 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK12-12-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK12-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK12",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK12-16",
      "NK 12/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4900-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4900.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 22,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.37,
    "static_load_kN": 8.15,
    "fatigue_load_limit_kN": 0.965,
    "max_rpm": 12000,
    "limiting_speed_rpm": 12000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4900.2RS is a ribbed machined-ring needle roller bearing (no inner ring) sized 14×22×13 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 14 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 14 mm Fw and 13 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 12,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 14 mm seat. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 14 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 7.37/8.15 kN ratings are SKF catalogue values for this exact execution (RNA 4900.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 7.37/8.15 kN ratings and 16 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 4900.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 14 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4900.2RS?",
        "a": "A RNA 4900.2RS measures 14 mm bore/Fw × 22 mm outside diameter × 13 mm width (0.551 × 0.866 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.37 kN, static C0 8.15 kN, fatigue limit Pu 0.965 kN, limiting speed 12,000 r/min, mass about 16 g."
      },
      {
        "q": "How is the RNA 4900.2RS designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 14 mm and width 13 mm, OD 22 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4900.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4900-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 14×22×13 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 14×22×13 mm envelope, but catalogue C/C0 differ between the executions (7.37/8.15 vs 8.8/10.4 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4900-2RS",
      "RNA 4900.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4900",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4900",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 22,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.8,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 1.22,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 17,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4900 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 14 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The RNA 4900 code states Fw 14 and width 13 mm directly; because the family has no inner ring, the 14 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 17 g at 14×22×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 14 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 8.8/10.4 kN ratings are SKF catalogue values for this exact execution (RNA 4900); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 8.8/10.4 kN ratings and 17 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 4900?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 14 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4900?",
        "a": "A RNA 4900 measures 14 mm bore/Fw × 22 mm outside diameter × 13 mm width (0.551 × 0.866 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.8 kN, static C0 10.4 kN, fatigue limit Pu 1.22 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 17 g."
      },
      {
        "q": "How is the RNA 4900 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 14 mm and width 13 mm, OD 22 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4900 run on an unhardened shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4900-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 14×22×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 14×22×13 mm envelope, but catalogue C/C0 differ between the executions (8.8/10.4 vs 7.37/8.15 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4900",
      "RNA 4900"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK14-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 14/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 22,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.2,
    "static_load_kN": 12.5,
    "fatigue_load_limit_kN": 1.5,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 14/16 designates a flanged, machined outer ring filled with needle rollers and a cage for a 14 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The NK 14/16 code states Fw 14 and width 16 mm directly; because the family has no inner ring, the 14 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 10.2/12.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 22 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NK 14/16 shares its 14×22×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 24,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 10.2/12.5 kN ratings and 21 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 14/16 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 14 mm and width 16 mm, OD 22 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 14/16 run on an unhardened shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 14/16 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 14 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 14/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 14 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK14-16-D-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 14×22×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK14-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 14×22×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK14-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK14",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK14-16",
      "NK 14/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK14-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 14/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 14,
    "D_mm": 22,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 2,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 14/20 is a ribbed machined-ring needle roller bearing (no inner ring) sized 14×22×20 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 14 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 14 mm Fw for the shaft seat, 20 mm width; the 22 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 12.8/16.6 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 14 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 24,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 14 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 12.8/16.6 kN ratings and 26 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 14/20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 14/20 have?",
        "a": "A NK 14/20 measures 14 mm bore/Fw × 22 mm outside diameter × 20 mm width (0.551 × 0.866 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.8 kN, static C0 16.6 kN, fatigue limit Pu 2 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 26 g."
      },
      {
        "q": "What does NK 14/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 14 mm and width 20 mm, OD 22 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 14/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 14 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK14-16-D-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK14-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK14-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 14×22×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK14",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK14-20",
      "NK 14/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK15-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 15/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 23,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 26000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 26000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 15/16: 15 mm Fw, 23 mm outside diameter, 16 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The NK 15/16 code states Fw 15 and width 16 mm directly; because the family has no inner ring, the 15 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 11/14 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 23 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 11/14 kN ratings are SKF catalogue values for this exact execution (NK 15/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 11/14 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 15/16 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 15 mm and width 16 mm, OD 23 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 15/16 run on an unhardened shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 15/16 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 15/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK15-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×23×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK15-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK15-16",
      "NK 15/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK15-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 15/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 23,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.8,
    "static_load_kN": 18.3,
    "fatigue_load_limit_kN": 2.2,
    "max_rpm": 26000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 26000,
    "weight_g": 27,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 15/20 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 15 mm bore seat and 23 mm OD. Reading the designation: NK gives the series and the numbers the boundary plan — 15 mm Fw for the shaft seat, 20 mm width; the 23 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 13.8/18.3 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 23 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 13.8/18.3 kN ratings are SKF catalogue values for this exact execution (NK 15/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 13.8/18.3 kN ratings and 27 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 15/20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 15/20 have?",
        "a": "A NK 15/20 measures 15 mm bore/Fw × 23 mm outside diameter × 20 mm width (0.591 × 0.906 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.8 kN, static C0 18.3 kN, fatigue limit Pu 2.2 kN, limiting speed 26,000 r/min, reference speed 24,000 r/min, mass about 27 g."
      },
      {
        "q": "What does NK 15/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 15 mm and width 20 mm, OD 23 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 15/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 15 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK15-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK15-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×23×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK15-20",
      "NK 15/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4901-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4901.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 24,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.09,
    "static_load_kN": 9.65,
    "fatigue_load_limit_kN": 1.14,
    "max_rpm": 11000,
    "limiting_speed_rpm": 11000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4901.2RS belongs to the machined-ring needle roller family: an outer ring turned and ground to 24 mm with two retaining flanges, a roller-and-cage set inside, and envelope 16×24×13 mm on a hardened 16 mm shaft. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 16 mm under-roller diameter and the 13 mm width, with the 24 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 18 g at 16×24×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 24 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 16 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 8.09/9.65 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 4901.2RS have?",
        "a": "A RNA 4901.2RS measures 16 mm bore/Fw × 24 mm outside diameter × 13 mm width (0.63 × 0.945 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.09 kN, static C0 9.65 kN, fatigue limit Pu 1.14 kN, limiting speed 11,000 r/min, mass about 18 g."
      },
      {
        "q": "What does RNA 4901.2RS mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 16 mm and width 13 mm, OD 24 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4901.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4901.2RS?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 16 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4901-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 16×24×13 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 16×24×13 mm envelope, but catalogue C/C0 differ between the executions (8.09/9.65 vs 9.9/12.2 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4901-2RS",
      "RNA 4901.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4901",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4901",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 24,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.9,
    "static_load_kN": 12.2,
    "fatigue_load_limit_kN": 1.46,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 17,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4901: 16 mm Fw, 24 mm outside diameter, 13 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 16 mm under-roller diameter and the 13 mm width, with the 24 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 17 g at 16×24×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 16 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 9.9/12.2 kN ratings and 17 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 4901?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 16 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4901 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4901 have?",
        "a": "A RNA 4901 measures 16 mm bore/Fw × 24 mm outside diameter × 13 mm width (0.63 × 0.945 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.9 kN, static C0 12.2 kN, fatigue limit Pu 1.46 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 17 g."
      },
      {
        "q": "What does RNA 4901 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 16 mm and width 13 mm, OD 24 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4901-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 16×24×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 16×24×13 mm envelope, but catalogue C/C0 differ between the executions (9.9/12.2 vs 8.09/9.65 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4901",
      "RNA 4901"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK16-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 16/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 24,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.7,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.8,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 16/16 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 16 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 16 mm under-roller diameter and the 16 mm width, with the 24 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. The 22 g catalogue mass and 4.0 mm radial section ((24−16)/2) frame a rating of about 0.73 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 11.7/15.3 kN ratings are SKF catalogue values for this exact execution (NK 16/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 11.7/15.3 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 16/16 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 16 mm and width 16 mm, OD 24 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 16/16 need a hardened and ground shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 16/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 16 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 16/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK16-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 16×24×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK16-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK16",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK16-16",
      "NK 16/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK16-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 16/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 24,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 20,
    "fatigue_load_limit_kN": 2.4,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 28,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 16/20 belongs to the machined-ring needle roller family: an outer ring turned and ground to 24 mm with two retaining flanges, a roller-and-cage set inside, and envelope 16×24×20 mm on a hardened 16 mm shaft. The NK 16/20 code states Fw 16 and width 20 mm directly; because the family has no inner ring, the 16 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. The 28 g catalogue mass and 4.0 mm radial section ((24−16)/2) frame a rating of about 0.91 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 24 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 14.5/20 kN ratings and 28 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NK 16/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 16 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 16/20?",
        "a": "A NK 16/20 measures 16 mm bore/Fw × 24 mm outside diameter × 20 mm width (0.63 × 0.945 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 14.5 kN, static C0 20 kN, fatigue limit Pu 2.4 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 28 g."
      },
      {
        "q": "How is the NK 16/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 16 mm and width 20 mm, OD 24 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 16/20 run on an unhardened shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK16-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK16-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 16×24×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK16",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK16-20",
      "NK 16/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6901",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6901",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 16,
    "D_mm": 24,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.1,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 2.75,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 31,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6901 is a ribbed machined-ring needle roller bearing (no inner ring) sized 16×24×22 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 16 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 16 mm Fw and 22 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 16.1/23.2 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 16 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 16.1/23.2 kN ratings and 31 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 6901 run on an unhardened shaft?",
        "a": "No. In this execution the 16 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 6901 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 16 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 6901?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 16 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 6901?",
        "a": "A RNA 6901 measures 16 mm bore/Fw × 24 mm outside diameter × 22 mm width (0.63 × 0.945 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.1 kN, static C0 23.2 kN, fatigue limit Pu 2.75 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 31 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6901-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 16×24×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6901",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6901",
      "RNA 6901"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK17-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 17/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 25,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 24,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 17/16 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 17 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 17 mm under-roller diameter and the 16 mm width, with the 25 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 24 g catalogue mass and 4.0 mm radial section ((25−17)/2) frame a rating of about 0.71 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 25 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 17/16 shares its 17×25×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 12.1/16.6 kN ratings and 24 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 17/16 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 17 mm and width 16 mm, OD 25 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 17/16 need a hardened and ground shaft?",
        "a": "No. In this execution the 17 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 17/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 17/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK17-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×25×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK17-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK17-16",
      "NK 17/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK17-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 17/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 25,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 22,
    "fatigue_load_limit_kN": 2.65,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 17/20 belongs to the machined-ring needle roller family: an outer ring turned and ground to 25 mm with two retaining flanges, a roller-and-cage set inside, and envelope 17×25×20 mm on a hardened 17 mm shaft. The NK 17/20 code states Fw 17 and width 20 mm directly; because the family has no inner ring, the 17 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 30 g catalogue mass and 4.0 mm radial section ((25−17)/2) frame a rating of about 0.89 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 25 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NK 17/20 shares its 17×25×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 15.1/22 kN ratings and 30 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NK 17/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 17/20?",
        "a": "A NK 17/20 measures 17 mm bore/Fw × 25 mm outside diameter × 20 mm width (0.669 × 0.984 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 22 kN, fatigue limit Pu 2.65 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 30 g."
      },
      {
        "q": "How is the NK 17/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 17 mm and width 20 mm, OD 25 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 17/20 run on an unhardened shaft?",
        "a": "No. In this execution the 17 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK17-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK17-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×25×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK17-20",
      "NK 17/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK18-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 18/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 18,
    "D_mm": 26,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 17.6,
    "fatigue_load_limit_kN": 2.12,
    "max_rpm": 24000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 24000,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 18/16 is a ribbed machined-ring needle roller bearing (no inner ring) sized 18×26×16 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 18 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 18 mm Fw and 16 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: 22,000 r/min thermal reference and 24,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 18 mm seat. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 18 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NK 18/16 shares its 18×26×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 12.8/17.6 kN ratings and 25 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 18/16 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 18 mm and width 16 mm, OD 26 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 18/16 run on an unhardened shaft?",
        "a": "No. In this execution the 18 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 18/16 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 18 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 18/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 18 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK18-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK18-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK18",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK18-16",
      "NK 18/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK18-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 18/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 18,
    "D_mm": 26,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.1,
    "static_load_kN": 23.6,
    "fatigue_load_limit_kN": 2.85,
    "max_rpm": 24000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 24000,
    "weight_g": 31,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 18/20 designates a flanged, machined outer ring filled with needle rollers and a cage for a 18 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 18 mm under-roller diameter and the 20 mm width, with the 26 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: 22,000 r/min thermal reference and 24,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 18 mm seat. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 26 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 18 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 18 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 16.1/23.6 kN ratings and 31 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 18/20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 18/20 have?",
        "a": "A NK 18/20 measures 18 mm bore/Fw × 26 mm outside diameter × 20 mm width (0.709 × 1.024 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.1 kN, static C0 23.6 kN, fatigue limit Pu 2.85 kN, limiting speed 24,000 r/min, reference speed 22,000 r/min, mass about 31 g."
      },
      {
        "q": "What does NK 18/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 18 mm and width 20 mm, OD 26 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 18/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 18 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK18-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK18-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 18×26×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK18",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK18-20",
      "NK 18/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK19-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 19/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 19,
    "D_mm": 27,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.4,
    "static_load_kN": 19,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 24000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 24000,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 19/16 is a ribbed machined-ring needle roller bearing (no inner ring) sized 19×27×16 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 19 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 19 mm Fw for the shaft seat, 16 mm width; the 27 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Selection arithmetic: C 13.4 kN against C0 19 kN gives a C0/C ratio of 1.42, and the 2.28 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 19 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 27 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 20,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 19 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 13.4/19 kN ratings and 26 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 19/16 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 19 mm and width 16 mm, OD 27 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 19/16 need a hardened and ground shaft?",
        "a": "No. In this execution the 19 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 19/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 19 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 19/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK19-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK19-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK19",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK19-16",
      "NK 19/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK19-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 19/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 19,
    "D_mm": 27,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 24000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 24000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 19/20 designates a flanged, machined outer ring filled with needle rollers and a cage for a 19 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 19 mm Fw and 20 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Selection arithmetic: C 16.5 kN against C0 25.5 kN gives a C0/C ratio of 1.55, and the 3.05 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 19 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 27 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 19 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 16.5/25.5 kN ratings are SKF catalogue values for this exact execution (NK 19/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 16.5/25.5 kN ratings and 32 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 626); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NK 19/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 19 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 19/20?",
        "a": "A NK 19/20 measures 19 mm bore/Fw × 27 mm outside diameter × 20 mm width (0.748 × 1.063 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.5 kN, static C0 25.5 kN, fatigue limit Pu 3.05 kN, limiting speed 24,000 r/min, reference speed 20,000 r/min, mass about 32 g."
      },
      {
        "q": "How is the NK 19/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 19 mm and width 20 mm, OD 27 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 19/20 run on an unhardened shaft?",
        "a": "No. In this execution the 19 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK19-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK19-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 19×27×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK19",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK19-20",
      "NK 19/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4902-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4902.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 28,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12,
    "fatigue_load_limit_kN": 1.43,
    "max_rpm": 9500,
    "limiting_speed_rpm": 9500,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4902.2RS: 20 mm Fw, 28 mm outside diameter, 13 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 20 mm under-roller diameter and the 13 mm width, with the 28 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 9,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 20 mm seat. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 28 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4902.2RS shares its 20×28×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 9.13/12 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 4902.2RS have?",
        "a": "A RNA 4902.2RS measures 20 mm bore/Fw × 28 mm outside diameter × 13 mm width (0.787 × 1.102 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12 kN, fatigue limit Pu 1.43 kN, limiting speed 9,500 r/min, mass about 22 g."
      },
      {
        "q": "What does RNA 4902.2RS mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 20 mm and width 13 mm, OD 28 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4902.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4902.2RS?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4902-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×28×13 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×28×13 mm envelope, but catalogue C/C0 differ between the executions (9.13/12 vs 11.2/15.3 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4902-2RS",
      "RNA 4902.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4902",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4902",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 28,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.2,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.83,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4902 designates a flanged, machined outer ring filled with needle rollers and a cage for a 20 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 20 mm Fw and 13 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 22 g at 20×28×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: RNA 4902 shares its 20×28×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 11.2/15.3 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 4902 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4902 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4902?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4902?",
        "a": "A RNA 4902 measures 20 mm bore/Fw × 28 mm outside diameter × 13 mm width (0.787 × 1.102 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.2 kN, static C0 15.3 kN, fatigue limit Pu 1.83 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 22 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4902-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×28×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×28×13 mm envelope, but catalogue C/C0 differ between the executions (11.2/15.3 vs 9.13/12 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4902",
      "RNA 4902"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK20-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 20/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 28,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 19.3,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 27,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 20/16 designates a flanged, machined outer ring filled with needle rollers and a cage for a 20 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 20 mm under-roller diameter and the 16 mm width, with the 28 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 20/16 shares its 20×28×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 13.2/19.3 kN ratings and 27 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NK 20/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 20/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 20/16 have?",
        "a": "A NK 20/16 measures 20 mm bore/Fw × 28 mm outside diameter × 16 mm width (0.787 × 1.102 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.2 kN, static C0 19.3 kN, fatigue limit Pu 2.28 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 27 g."
      },
      {
        "q": "What does NK 20/16 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 20 mm and width 16 mm, OD 28 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK20-16-D-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×28×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK20-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×28×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK20-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK20-16",
      "NK 20/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK20-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 20/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 28,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 20/20 is a ribbed machined-ring needle roller bearing (no inner ring) sized 20×28×20 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 20 mm shaft journal completes the bearing. The NK 20/20 code states Fw 20 and width 20 mm directly; because the family has no inner ring, the 20 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NK 20/20 shares its 20×28×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 16.5/25.5 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 20/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 20 mm and width 20 mm, OD 28 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 20/20 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 20/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 20/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK20-16-D-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK20-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK20-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×28×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK20-20",
      "NK 20/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6902",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6902",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 28,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.2,
    "static_load_kN": 27,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6902 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 20 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: RNA gives the series and the numbers the boundary plan — 20 mm Fw for the shaft seat, 23 mm width; the 28 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 17.2/27 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 17.2/27 kN ratings are SKF catalogue values for this exact execution (RNA 6902); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 17.2/27 kN ratings and 40 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 6902 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 20 mm and width 23 mm, OD 28 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 6902 need a hardened and ground shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 6902?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 6902 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6902-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×28×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6902",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6902",
      "RNA 6902"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS20",
    "brand": "SKF",
    "manufacturer_designation": "NKS 20",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 27,
    "fatigue_load_limit_kN": 3.25,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 49,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 20 belongs to the machined-ring needle roller family: an outer ring turned and ground to 32 mm with two retaining flanges, a roller-and-cage set inside, and envelope 20×32×20 mm on a hardened 20 mm shaft. The NKS 20 code states Fw 20 and width 20 mm directly; because the family has no inner ring, the 20 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 32 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKS 20 shares its 20×32×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 18,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 23.3/27 kN ratings and 49 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKS 20 run on an unhardened shaft?",
        "a": "No. In this execution the 20 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NKS 20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKS 20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 20?",
        "a": "A NKS 20 measures 20 mm bore/Fw × 32 mm outside diameter × 20 mm width (0.787 × 1.26 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 27 kN, fatigue limit Pu 3.25 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 49 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI20-20",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×20 mm envelope, but catalogue C/C0 differ between the executions (23.3/27 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS20",
      "NKS 20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK21-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 21/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 21,
    "D_mm": 29,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.8,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 2.45,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 28,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 21/16 designates a flanged, machined outer ring filled with needle rollers and a cage for a 21 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 21 mm under-roller diameter and the 16 mm width, with the 29 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 29 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 21 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 29 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 21 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 13.8/20.4 kN ratings and 28 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NK 21/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 21 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 21/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 21/16 have?",
        "a": "A NK 21/16 measures 21 mm bore/Fw × 29 mm outside diameter × 16 mm width (0.827 × 1.142 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.8 kN, static C0 20.4 kN, fatigue limit Pu 2.45 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 28 g."
      },
      {
        "q": "What does NK 21/16 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 21 mm and width 16 mm, OD 29 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK21-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK21-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK21",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK21-16",
      "NK 21/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK21-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 21/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 21,
    "D_mm": 29,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.2,
    "static_load_kN": 27,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 35,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 21/20 is a ribbed machined-ring needle roller bearing (no inner ring) sized 21×29×20 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 21 mm shaft journal completes the bearing. The NK 21/20 code states Fw 21 and width 20 mm directly; because the family has no inner ring, the 21 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 21 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 29 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 21 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 17.2/27 kN ratings are SKF catalogue values for this exact execution (NK 21/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 17.2/27 kN ratings and 35 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 21/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 21 mm and width 20 mm, OD 29 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 21/20 run on an unhardened shaft?",
        "a": "No. In this execution the 21 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 21/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 21 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 21/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 21 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK21-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK21-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 21×29×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK21",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK21-20",
      "NK 21/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4903-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4903.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 30,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.52,
    "static_load_kN": 12.9,
    "fatigue_load_limit_kN": 1.53,
    "max_rpm": 9000,
    "limiting_speed_rpm": 9000,
    "weight_g": 23,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4903.2RS is a ribbed machined-ring needle roller bearing (no inner ring) sized 22×30×13 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 22 mm shaft journal completes the bearing. The RNA 4903.2RS code states Fw 22 and width 13 mm directly; because the family has no inner ring, the 22 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Catalogue mass 23 g at 22×30×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 9.52/12.9 kN ratings and 23 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 4903.2RS designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 22 mm and width 13 mm, OD 30 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4903.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4903.2RS be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4903.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 22 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4903-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×30×13 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 22×30×13 mm envelope, but catalogue C/C0 differ between the executions (9.52/12.9 vs 11.4/16.3 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4903-2RS",
      "RNA 4903.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4903",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4903",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 30,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.4,
    "static_load_kN": 16.3,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4903 belongs to the machined-ring needle roller family: an outer ring turned and ground to 30 mm with two retaining flanges, a roller-and-cage set inside, and envelope 22×30×13 mm on a hardened 22 mm shaft. Reading the designation: RNA gives the series and the numbers the boundary plan — 22 mm Fw for the shaft seat, 13 mm width; the 30 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 22 g at 22×30×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4903 shares its 22×30×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 11.4/16.3 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 4903 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 22 mm and width 13 mm, OD 30 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4903 need a hardened and ground shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4903?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4903 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4903-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×30×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 22×30×13 mm envelope, but catalogue C/C0 differ between the executions (11.4/16.3 vs 9.52/12.9 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4903",
      "RNA 4903"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK22-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 22/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 30,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 21.6,
    "fatigue_load_limit_kN": 2.6,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 22/16: 22 mm Fw, 30 mm outside diameter, 16 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 22 mm Fw and 16 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 14.2/21.6 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 14.2/21.6 kN ratings are SKF catalogue values for this exact execution (NK 22/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 14.2/21.6 kN ratings and 30 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NK 22/16 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 22/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 22 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 22/16?",
        "a": "A NK 22/16 measures 22 mm bore/Fw × 30 mm outside diameter × 16 mm width (0.866 × 1.181 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 14.2 kN, static C0 21.6 kN, fatigue limit Pu 2.6 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 30 g."
      },
      {
        "q": "How is the NK 22/16 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 22 mm and width 16 mm, OD 30 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK22-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×30×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK22-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK22",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK22-16",
      "NK 22/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK22-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 22/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 30,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.9,
    "static_load_kN": 29,
    "fatigue_load_limit_kN": 3.55,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 22/20 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 22 mm bore seat and 30 mm OD. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 22 mm under-roller diameter and the 20 mm width, with the 30 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 17.9/29 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 17.9/29 kN ratings are SKF catalogue values for this exact execution (NK 22/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 17.9/29 kN ratings and 37 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 22/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 22 mm and width 20 mm, OD 30 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 22/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 22/20?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 22/20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK22-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK22-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×30×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK22",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK22-20",
      "NK 22/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6903",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6903",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 30,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 18.7,
    "static_load_kN": 30.5,
    "fatigue_load_limit_kN": 3.75,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 69 needle roller bearings without inner ring include RNA 6903: 22 mm Fw, 30 mm outside diameter, 23 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The RNA 6903 code states Fw 22 and width 23 mm directly; because the family has no inner ring, the 22 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 18.7/30.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 18.7/30.5 kN ratings are SKF catalogue values for this exact execution (RNA 6903); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 18.7/30.5 kN ratings and 42 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 6903?",
        "a": "A RNA 6903 measures 22 mm bore/Fw × 30 mm outside diameter × 23 mm width (0.866 × 1.181 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 18.7 kN, static C0 30.5 kN, fatigue limit Pu 3.75 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 42 g."
      },
      {
        "q": "How is the RNA 6903 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 22 mm and width 23 mm, OD 30 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 6903 run on an unhardened shaft?",
        "a": "No. In this execution the 22 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 6903 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6903-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×30×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6903",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6903",
      "RNA 6903"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK24-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 24/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 24,
    "D_mm": 32,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.4,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 2.9,
    "max_rpm": 19000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 19000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 24/16 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 24 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: NK gives the series and the numbers the boundary plan — 24 mm Fw for the shaft seat, 16 mm width; the 32 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: 16,000 r/min thermal reference and 19,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 24 mm seat. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 24 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 24/16 shares its 24×32×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 15.4/24.5 kN ratings and 32 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 24/16 need a hardened and ground shaft?",
        "a": "No. In this execution the 24 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 24/16?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 24 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 24/16 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 24/16 have?",
        "a": "A NK 24/16 measures 24 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.945 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.4 kN, static C0 24.5 kN, fatigue limit Pu 2.9 kN, limiting speed 19,000 r/min, reference speed 16,000 r/min, mass about 32 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK24-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK24-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK24",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK24-16",
      "NK 24/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK24-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 24/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 24,
    "D_mm": 32,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 19000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 19000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 24/20 belongs to the machined-ring needle roller family: an outer ring turned and ground to 32 mm with two retaining flanges, a roller-and-cage set inside, and envelope 24×32×20 mm on a hardened 24 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 24 mm Fw and 20 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: 16,000 r/min thermal reference and 19,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 24 mm seat. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 32 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 24 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NK 24/20 shares its 24×32×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 16,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 19/32.5 kN ratings and 40 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 24/20?",
        "a": "A NK 24/20 measures 24 mm bore/Fw × 32 mm outside diameter × 20 mm width (0.945 × 1.26 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 19,000 r/min, reference speed 16,000 r/min, mass about 40 g."
      },
      {
        "q": "How is the NK 24/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 24 mm and width 20 mm, OD 32 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 24/20 run on an unhardened shaft?",
        "a": "No. In this execution the 24 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 24/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 24 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK24-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK24-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 24×32×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK24",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK24-20",
      "NK 24/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS24",
    "brand": "SKF",
    "manufacturer_designation": "NKS 24",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 24,
    "D_mm": 37,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26,
    "static_load_kN": 33.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 66,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's wide-section machined-ring needle roller bearings without inner ring include NKS 24: 24 mm Fw, 37 mm outside diameter, 20 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The NKS 24 code states Fw 24 and width 20 mm directly; because the family has no inner ring, the 24 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 37 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 24 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 24 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 26/33.5 kN ratings are SKF catalogue values for this exact execution (NKS 24); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 26/33.5 kN ratings and 66 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKS 24 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 24 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKS 24?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 24 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 24?",
        "a": "A NKS 24 measures 24 mm bore/Fw × 37 mm outside diameter × 20 mm width (0.945 × 1.457 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26 kN, static C0 33.5 kN, fatigue limit Pu 4 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 66 g."
      },
      {
        "q": "How is the NKS 24 designation read?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 24 mm and width 20 mm, OD 37 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS24-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 24×37×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS24",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS24",
      "NKS 24"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK25-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 25/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 33,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 2.9,
    "max_rpm": 18000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 18000,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 25/16 is a ribbed machined-ring needle roller bearing (no inner ring) sized 25×33×16 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 25 mm shaft journal completes the bearing. The NK 25/16 code states Fw 25 and width 16 mm directly; because the family has no inner ring, the 25 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Selection arithmetic: C 15.1 kN against C0 24.5 kN gives a C0/C ratio of 1.62, and the 2.9 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 33 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 33 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NK 25/16 shares its 25×33×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 16,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 15.1/24.5 kN ratings and 33 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 25/16 run on an unhardened shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 25/16 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 25/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 25/16?",
        "a": "A NK 25/16 measures 25 mm bore/Fw × 33 mm outside diameter × 16 mm width (0.984 × 1.299 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 24.5 kN, fatigue limit Pu 2.9 kN, limiting speed 18,000 r/min, reference speed 16,000 r/min, mass about 33 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK25-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×33×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK25-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK25-16",
      "NK 25/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK25-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 25/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 33,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 18000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 18000,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 25/20 designates a flanged, machined outer ring filled with needle rollers and a cage for a 25 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. Reading the designation: NK gives the series and the numbers the boundary plan — 25 mm Fw for the shaft seat, 20 mm width; the 33 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Selection arithmetic: C 19 kN against C0 32.5 kN gives a C0/C ratio of 1.71, and the 4 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 33 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 16,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 19/32.5 kN ratings and 42 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NK 25/20 have?",
        "a": "A NK 25/20 measures 25 mm bore/Fw × 33 mm outside diameter × 20 mm width (0.984 × 1.299 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 18,000 r/min, reference speed 16,000 r/min, mass about 42 g."
      },
      {
        "q": "What does NK 25/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 25 mm and width 20 mm, OD 33 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 25/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 25/20?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK25-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK25-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×33×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK25-20",
      "NK 25/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4904-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4904.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19.4,
    "static_load_kN": 22.4,
    "fatigue_load_limit_kN": 2.65,
    "max_rpm": 7500,
    "limiting_speed_rpm": 7500,
    "weight_g": 56,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4904.2RS belongs to the machined-ring needle roller family: an outer ring turned and ground to 37 mm with two retaining flanges, a roller-and-cage set inside, and envelope 25×37×17 mm on a hardened 25 mm shaft. Reading the designation: RNA gives the series and the numbers the boundary plan — 25 mm Fw for the shaft seat, 17 mm width; the 37 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 19.4/22.4 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 19.4/22.4 kN ratings are SKF catalogue values for this exact execution (RNA 4904.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 19.4/22.4 kN ratings and 56 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RNA 4904.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4904.2RS?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4904.2RS sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4904.2RS have?",
        "a": "A RNA 4904.2RS measures 25 mm bore/Fw × 37 mm outside diameter × 17 mm width (0.984 × 1.457 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19.4 kN, static C0 22.4 kN, fatigue limit Pu 2.65 kN, limiting speed 7,500 r/min, mass about 56 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4904-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×17 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×17 mm envelope, but catalogue C/C0 differ between the executions (19.4/22.4 vs 21.6/28 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4904-2RS",
      "RNA 4904.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4904",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4904",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 28,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 4904 in the dimension series 49 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 25 mm bore seat and 37 mm OD. The RNA 4904 code states Fw 25 and width 17 mm directly; because the family has no inner ring, the 25 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 52 g at 25×37×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 21.6/28 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 4904?",
        "a": "A RNA 4904 measures 25 mm bore/Fw × 37 mm outside diameter × 17 mm width (0.984 × 1.457 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 28 kN, fatigue limit Pu 3.35 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 52 g."
      },
      {
        "q": "How is the RNA 4904 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 25 mm and width 17 mm, OD 37 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4904 run on an unhardened shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4904 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4904-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "RNA4904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×17 mm envelope, but catalogue C/C0 differ between the executions (21.6/28 vs 19.4/22.4 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4904",
      "RNA 4904"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6904",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6904",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 35.2,
    "static_load_kN": 53,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 6904 designates a flanged, machined outer ring filled with needle rollers and a cage for a 25 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 25 mm under-roller diameter and the 30 mm width, with the 37 mm outside diameter set by the dimension series 69 needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 35.2/53 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 35.2/53 kN ratings and 100 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the RNA 6904 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 6904 have?",
        "a": "A RNA 6904 measures 25 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.984 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 35.2 kN, static C0 53 kN, fatigue limit Pu 6.55 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 100 g."
      },
      {
        "q": "What does RNA 6904 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 25 mm and width 30 mm, OD 37 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 6904 need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6904-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (35.2/53 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (35.2/53 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (35.2/53 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (35.2/53 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (35.2/53 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (35.2/53 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6904",
      "RNA 6904"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS25",
    "brand": "SKF",
    "manufacturer_designation": "NKS 25",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 38,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 36,
    "fatigue_load_limit_kN": 4.4,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 68,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKS 25 designates a flanged, machined outer ring filled with needle rollers and a cage for a 25 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NKS families drop the inner ring: the numbers after the letters give the 25 mm under-roller diameter and the 20 mm width, with the 38 mm outside diameter set by the wide-section machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 38 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 38 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 27.5/36 kN ratings and 68 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKS 25 need a hardened and ground shaft?",
        "a": "No. In this execution the 25 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NKS 25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKS 25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKS 25 have?",
        "a": "A NKS 25 measures 25 mm bore/Fw × 38 mm outside diameter × 20 mm width (0.984 × 1.496 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 36 kN, fatigue limit Pu 4.4 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 68 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×38×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI25-20-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×38×20 mm envelope, but catalogue C/C0 differ between the executions (27.5/36 vs 24.6/42.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS25",
      "NKS 25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK26-16",
    "brand": "SKF",
    "manufacturer_designation": "NK 26/16",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 26,
    "D_mm": 34,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.7,
    "static_load_kN": 26,
    "fatigue_load_limit_kN": 3.1,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 26/16 is a ribbed machined-ring needle roller bearing (no inner ring) sized 26×34×16 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 26 mm shaft journal completes the bearing. The NK 26/16 code states Fw 26 and width 16 mm directly; because the family has no inner ring, the 26 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Selection arithmetic: C 15.7 kN against C0 26 kN gives a C0/C ratio of 1.66, and the 3.1 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 26 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 26 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 26 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 15.7/26 kN ratings are SKF catalogue values for this exact execution (NK 26/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 15.7/26 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 26/16 run on an unhardened shaft?",
        "a": "No. In this execution the 26 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 26/16 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 26 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 26/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 26 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 26/16?",
        "a": "A NK 26/16 measures 26 mm bore/Fw × 34 mm outside diameter × 16 mm width (1.024 × 1.339 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.7 kN, static C0 26 kN, fatigue limit Pu 3.1 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 34 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK26-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 26×34×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK26-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK26",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK26-16",
      "NK 26/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK26-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 26/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 26,
    "D_mm": 34,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19.4,
    "static_load_kN": 34.5,
    "fatigue_load_limit_kN": 4.25,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 26/20 designates a flanged, machined outer ring filled with needle rollers and a cage for a 26 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. Reading the designation: NK gives the series and the numbers the boundary plan — 26 mm Fw for the shaft seat, 20 mm width; the 34 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Selection arithmetic: C 19.4 kN against C0 34.5 kN gives a C0/C ratio of 1.78, and the 4.25 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 34 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 26 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 26 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 19.4/34.5 kN ratings are SKF catalogue values for this exact execution (NK 26/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 19.4/34.5 kN ratings and 42 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NK 26/20 have?",
        "a": "A NK 26/20 measures 26 mm bore/Fw × 34 mm outside diameter × 20 mm width (1.024 × 1.339 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19.4 kN, static C0 34.5 kN, fatigue limit Pu 4.25 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 42 g."
      },
      {
        "q": "What does NK 26/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 26 mm and width 20 mm, OD 34 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 26/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 26 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 26/20?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 26 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK26-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK26-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 26×34×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK26",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK26-20",
      "NK 26/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK28-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 28/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 37,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 4.55,
    "max_rpm": 16000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 16000,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 28/20 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 28 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The NK 28/20 code states Fw 28 and width 20 mm directly; because the family has no inner ring, the 28 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 52 g at 28×37×20 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NK 28/20 shares its 28×37×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 14,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 22/36.5 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 28/20?",
        "a": "A NK 28/20 measures 28 mm bore/Fw × 37 mm outside diameter × 20 mm width (1.102 × 1.457 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22 kN, static C0 36.5 kN, fatigue limit Pu 4.55 kN, limiting speed 16,000 r/min, reference speed 14,000 r/min, mass about 52 g."
      },
      {
        "q": "How is the NK 28/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 28 mm and width 20 mm, OD 37 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 28/20 run on an unhardened shaft?",
        "a": "No. In this execution the 28 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 28/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 28 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK28-20-D-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×37×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK28-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×37×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK28-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK28",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK28-20",
      "NK 28/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK28-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 28/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 16000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 16000,
    "weight_g": 82,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 28/30 belongs to the machined-ring needle roller family: an outer ring turned and ground to 37 mm with two retaining flanges, a roller-and-cage set inside, and envelope 28×37×30 mm on a hardened 28 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 28 mm under-roller diameter and the 30 mm width, with the 37 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 82 g at 28×37×30 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 37 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 14,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 28 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 31.9/60 kN ratings and 82 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 28/30 need a hardened and ground shaft?",
        "a": "No. In this execution the 28 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 28/30?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 28 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 28/30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 28/30 have?",
        "a": "A NK 28/30 measures 28 mm bore/Fw × 37 mm outside diameter × 30 mm width (1.102 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 60 kN, fatigue limit Pu 7.5 kN, limiting speed 16,000 r/min, reference speed 14,000 r/min, mass about 82 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK28-20-D-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK28-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK28-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×37×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK28",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK28-30",
      "NK 28/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA49-22",
    "brand": "SKF",
    "manufacturer_designation": "RNA 49/22",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 39,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.9,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 49/22 is a ribbed machined-ring needle roller bearing (no inner ring) sized 28×39×17 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 28 mm shaft journal completes the bearing. Reading the designation: RNA gives the series and the numbers the boundary plan — 28 mm Fw for the shaft seat, 17 mm width; the 39 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. The 50 g catalogue mass and 5.5 mm radial section ((39−28)/2) frame a rating of about 0.83 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 39 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 49/22 shares its 28×39×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 23.3/32 kN ratings and 50 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the RNA 49/22 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 49/22 have?",
        "a": "A RNA 49/22 measures 28 mm bore/Fw × 39 mm outside diameter × 17 mm width (1.102 × 1.535 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 32 kN, fatigue limit Pu 3.9 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 50 g."
      },
      {
        "q": "What does RNA 49/22 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 28 mm and width 17 mm, OD 39 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 49/22 need a hardened and ground shaft?",
        "a": "No. In this execution the 28 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA49-22-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×39×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA49-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA49-32-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA49",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA49-22",
      "RNA 49/22"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA69-22",
    "brand": "SKF",
    "manufacturer_designation": "RNA 69/22",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 39,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.2,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 98,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 69 needle roller bearings without inner ring include RNA 69/22: 28 mm Fw, 39 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 28 mm Fw and 30 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 36.9/57 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 28 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 36.9/57 kN ratings are SKF catalogue values for this exact execution (RNA 69/22); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 36.9/57 kN ratings and 98 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 69/22 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 28 mm and width 30 mm, OD 39 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 69/22 run on an unhardened shaft?",
        "a": "No. In this execution the 28 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 69/22 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 28 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 69/22?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 28 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA69-22-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×39×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA69-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA69-32-ZW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA69",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA69-22",
      "RNA 69/22"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS28",
    "brand": "SKF",
    "manufacturer_designation": "NKS 28",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 28.6,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.75,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 84,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 28 is a ribbed machined-ring needle roller bearing (no inner ring) sized 28×42×20 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 28 mm shaft journal completes the bearing. The NKS 28 code states Fw 28 and width 20 mm directly; because the family has no inner ring, the 28 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 42 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 28.6/39 kN ratings and 84 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKS 28?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 28 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 28?",
        "a": "A NKS 28 measures 28 mm bore/Fw × 42 mm outside diameter × 20 mm width (1.102 × 1.654 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 28.6 kN, static C0 39 kN, fatigue limit Pu 4.75 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 84 g."
      },
      {
        "q": "How is the NKS 28 designation read?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 28 mm and width 20 mm, OD 42 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NKS 28 run on an unhardened shaft?",
        "a": "No. In this execution the 28 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS28-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×42×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI28-20-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 28×42×20 mm envelope, but catalogue C/C0 differ between the executions (28.6/39 vs 26.4/48 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS28",
      "NKS 28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK29-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 29/20 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 29,
    "D_mm": 38,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 42.5,
    "fatigue_load_limit_kN": 5.2,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 29/20 TN designates a flanged, machined outer ring filled with needle rollers and a cage for a 29 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 29 mm Fw and 20 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. For life calculation, the 24.6/42.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 29 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 29 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 24.6/42.5 kN ratings and 50 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 29/20 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 29 mm and width 20 mm, OD 38 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 29/20 TN run on an unhardened shaft?",
        "a": "No. In this execution the 29 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 29/20 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 29 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 29/20 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 29 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK29-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 29×38×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK29-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK29-20-TN",
      "NK 29/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK29-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 29/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 29,
    "D_mm": 38,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 84,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 29/30 belongs to the machined-ring needle roller family: an outer ring turned and ground to 38 mm with two retaining flanges, a roller-and-cage set inside, and envelope 29×38×30 mm on a hardened 29 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 29 mm Fw and 30 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 31.9/60 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 38 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 29 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 29 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 29 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 31.9/60 kN ratings are SKF catalogue values for this exact execution (NK 29/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 31.9/60 kN ratings and 84 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 628); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 29/30 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 29 mm and width 30 mm, OD 38 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 29/30 run on an unhardened shaft?",
        "a": "No. In this execution the 29 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 29/30 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 29 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 29/30?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 29 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK29-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK29-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 29×38×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK29",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK29-30",
      "NK 29/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK30-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 30/20 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 40,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 25.1,
    "static_load_kN": 44,
    "fatigue_load_limit_kN": 5.5,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 61,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 30/20 TN belongs to the machined-ring needle roller family: an outer ring turned and ground to 40 mm with two retaining flanges, a roller-and-cage set inside, and envelope 30×40×20 mm on a hardened 30 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 30 mm Fw and 20 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Catalogue mass 61 g at 30×40×20 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 40 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 25.1/44 kN ratings and 61 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 30/20 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 30 mm and width 20 mm, OD 40 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 30/20 TN run on an unhardened shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 30/20 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 30/20 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK30-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×40×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK30-20-TW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×40×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK30-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK30-20-TN",
      "NK 30/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK30-30-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 30/30 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 40,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 72,
    "fatigue_load_limit_kN": 9,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 92,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 30/30 TN: 30 mm Fw, 40 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 30 mm under-roller diameter and the 30 mm width, with the 40 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 36.9/72 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 36.9/72 kN ratings are SKF catalogue values for this exact execution (NK 30/30 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 36.9/72 kN ratings and 92 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 30/30 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 30/30 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 30/30 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 30/30 TN have?",
        "a": "A NK 30/30 TN measures 30 mm bore/Fw × 40 mm outside diameter × 30 mm width (1.181 × 1.575 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 36.9 kN, static C0 72 kN, fatigue limit Pu 9 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 92 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK30-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK30-20-TW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK30-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×40×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK30-30-TN",
      "NK 30/30 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4905-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4905.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 27.5,
    "fatigue_load_limit_kN": 3.25,
    "max_rpm": 6300,
    "limiting_speed_rpm": 6300,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4905.2RS: 30 mm Fw, 42 mm outside diameter, 17 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. Reading the designation: RNA gives the series and the numbers the boundary plan — 30 mm Fw for the shaft seat, 17 mm width; the 42 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Selection arithmetic: C 21.6 kN against C0 27.5 kN gives a C0/C ratio of 1.27, and the 3.25 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 42 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 21.6/27.5 kN ratings and 60 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 4905.2RS?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4905.2RS sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4905.2RS have?",
        "a": "A RNA 4905.2RS measures 30 mm bore/Fw × 42 mm outside diameter × 17 mm width (1.181 × 1.654 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 27.5 kN, fatigue limit Pu 3.25 kN, limiting speed 6,300 r/min, mass about 60 g."
      },
      {
        "q": "What does RNA 4905.2RS mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 30 mm and width 17 mm, OD 42 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4905-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×17 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×17 mm envelope, but catalogue C/C0 differ between the executions (21.6/27.5 vs 24.2/34.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4905-2RS",
      "RNA 4905.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4905",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4905",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 34.5,
    "fatigue_load_limit_kN": 4.15,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 61,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4905 is a ribbed machined-ring needle roller bearing (no inner ring) sized 30×42×17 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 30 mm shaft journal completes the bearing. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 30 mm under-roller diameter and the 17 mm width, with the 42 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 61 g at 30×42×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 24.2/34.5 kN ratings are SKF catalogue values for this exact execution (RNA 4905); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 24.2/34.5 kN ratings and 61 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the RNA 4905 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4905 have?",
        "a": "A RNA 4905 measures 30 mm bore/Fw × 42 mm outside diameter × 17 mm width (1.181 × 1.654 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.2 kN, static C0 34.5 kN, fatigue limit Pu 4.15 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 61 g."
      },
      {
        "q": "What does RNA 4905 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 30 mm and width 17 mm, OD 42 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4905 need a hardened and ground shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4905-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "RNA4905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×17 mm envelope, but catalogue C/C0 differ between the executions (24.2/34.5 vs 21.6/27.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4905",
      "RNA 4905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6905",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6905",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 62,
    "fatigue_load_limit_kN": 7.65,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6905 belongs to the machined-ring needle roller family: an outer ring turned and ground to 42 mm with two retaining flanges, a roller-and-cage set inside, and envelope 30×42×30 mm on a hardened 30 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 30 mm Fw and 30 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 38/62 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: RNA 6905 shares its 30×42×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 13,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 38/62 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RNA 6905 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 6905?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 6905?",
        "a": "A RNA 6905 measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 62 kN, fatigue limit Pu 7.65 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 110 g."
      },
      {
        "q": "How is the RNA 6905 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 30 mm and width 30 mm, OD 42 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6905-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NX30-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (38/62 vs 22.9/38 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (38/62 vs 22.9/38 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX30-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (38/62 vs 22.9/38 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (38/62 vs 22.9/38 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (38/62 vs 22.9/38 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR30-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (38/62 vs 22.9/38 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6905",
      "RNA 6905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS30",
    "brand": "SKF",
    "manufacturer_designation": "NKS 30",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 45,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.3,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 30 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 30 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NKS families drop the inner ring: the numbers after the letters give the 30 mm under-roller diameter and the 22 mm width, with the 45 mm outside diameter set by the wide-section machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 12,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 31.9/43 kN ratings and 100 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKS 30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKS 30 have?",
        "a": "A NKS 30 measures 30 mm bore/Fw × 45 mm outside diameter × 22 mm width (1.181 × 1.772 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 43 kN, fatigue limit Pu 5.3 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 100 g."
      },
      {
        "q": "What does NKS 30 mean in SKF part numbering?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 30 mm and width 22 mm, OD 45 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NKS 30 need a hardened and ground shaft?",
        "a": "No. In this execution the 30 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×45×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS30",
      "NKS 30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK32-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 32/20 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 48,
    "fatigue_load_limit_kN": 6,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 64,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 32/20 TN is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 32 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: NK gives the series and the numbers the boundary plan — 32 mm Fw for the shaft seat, 20 mm width; the 42 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Selection arithmetic: C 26.4 kN against C0 48 kN gives a C0/C ratio of 1.82, and the 6 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 26.4/48 kN ratings are SKF catalogue values for this exact execution (NK 32/20 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 26.4/48 kN ratings and 64 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 32/20 TN mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 32 mm and width 20 mm, OD 42 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 32/20 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 32/20 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 32 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 32/20 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK32-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×42×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK32-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK32-20-TN",
      "NK 32/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK32-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 32/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 34.1,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 32/30 is a ribbed machined-ring needle roller bearing (no inner ring) sized 32×42×30 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 32 mm shaft journal completes the bearing. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 32 mm under-roller diameter and the 30 mm width, with the 42 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Speed planning separates the two ceilings: 12,000 r/min thermal reference and 14,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 32 mm seat. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 34.1/65.5 kN ratings are SKF catalogue values for this exact execution (NK 32/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 34.1/65.5 kN ratings and 100 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 32/30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 32/30 have?",
        "a": "A NK 32/30 measures 32 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.26 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 34.1 kN, static C0 65.5 kN, fatigue limit Pu 8.3 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 100 g."
      },
      {
        "q": "What does NK 32/30 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 32 mm and width 30 mm, OD 42 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 32/30 need a hardened and ground shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK32-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK32-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×42×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK32-30",
      "NK 32/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA49-28",
    "brand": "SKF",
    "manufacturer_designation": "RNA 49/28",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 45,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.1,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 4.4,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 73,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 49/28 is a ribbed machined-ring needle roller bearing (no inner ring) sized 32×45×17 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 32 mm shaft journal completes the bearing. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 32 mm under-roller diameter and the 17 mm width, with the 45 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. The 73 g catalogue mass and 6.5 mm radial section ((45−32)/2) frame a rating of about 0.78 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 45 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 49/28 shares its 32×45×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 25.1/36.5 kN ratings and 73 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 49/28?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 32 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 49/28 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 49/28 have?",
        "a": "A RNA 49/28 measures 32 mm bore/Fw × 45 mm outside diameter × 17 mm width (1.26 × 1.772 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.1 kN, static C0 36.5 kN, fatigue limit Pu 4.4 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 73 g."
      },
      {
        "q": "What does RNA 49/28 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 32 mm and width 17 mm, OD 45 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA49-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA49-28-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "RNA49-32-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA49",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA49-28",
      "RNA 49/28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA69-28",
    "brand": "SKF",
    "manufacturer_designation": "RNA 69/28",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 45,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.6,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 69 needle roller bearings without inner ring include RNA 69/28: 32 mm Fw, 45 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The RNA 69/28 code states Fw 32 and width 30 mm directly; because the family has no inner ring, the 32 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 39.6/65.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 32 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 39.6/65.5 kN ratings are SKF catalogue values for this exact execution (RNA 69/28); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 39.6/65.5 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 69/28?",
        "a": "A RNA 69/28 measures 32 mm bore/Fw × 45 mm outside diameter × 30 mm width (1.26 × 1.772 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.6 kN, static C0 65.5 kN, fatigue limit Pu 8.3 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 140 g."
      },
      {
        "q": "How is the RNA 69/28 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 32 mm and width 30 mm, OD 45 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 69/28 run on an unhardened shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 69/28 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 32 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA69-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA69-28-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×45×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA69-32-ZW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA69",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA69-28",
      "RNA 69/28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS32",
    "brand": "SKF",
    "manufacturer_designation": "NKS 32",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 47,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 34.1,
    "static_load_kN": 46.5,
    "fatigue_load_limit_kN": 5.7,
    "max_rpm": 13000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 13000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKS 32 designates a flanged, machined outer ring filled with needle rollers and a cage for a 32 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. Reading the designation: NKS gives the series and the numbers the boundary plan — 32 mm Fw for the shaft seat, 22 mm width; the 47 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKS 32 shares its 32×47×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 34.1/46.5 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKS 32 need a hardened and ground shaft?",
        "a": "No. In this execution the 32 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NKS 32?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 32 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKS 32 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKS 32 have?",
        "a": "A NKS 32 measures 32 mm bore/Fw × 47 mm outside diameter × 22 mm width (1.26 × 1.85 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 34.1 kN, static C0 46.5 kN, fatigue limit Pu 5.7 kN, limiting speed 13,000 r/min, reference speed 12,000 r/min, mass about 110 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS32-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×47×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS32",
      "NKS 32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK35-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 35/20 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 45,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 52,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 35/20 TN designates a flanged, machined outer ring filled with needle rollers and a cage for a 35 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 35 mm Fw and 20 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Selection arithmetic: C 27.5 kN against C0 52 kN gives a C0/C ratio of 1.89, and the 6.55 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 45 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NK 35/20 TN shares its 35×45×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 27.5/52 kN ratings and 69 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 35/20 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 35 mm and width 20 mm, OD 45 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 35/20 TN run on an unhardened shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 35/20 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 35/20 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK35-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×45×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK35-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK35-20-TN",
      "NK 35/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK35-30-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 35/30 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 45,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 85,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 35/30 TN is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 35 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 35 mm under-roller diameter and the 30 mm width, with the 45 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 35/30 TN shares its 35×45×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 40.2/85 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 35/30 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 35/30 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 35/30 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 35/30 TN have?",
        "a": "A NK 35/30 TN measures 35 mm bore/Fw × 45 mm outside diameter × 30 mm width (1.378 × 1.772 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 40.2 kN, static C0 85 kN, fatigue limit Pu 10.6 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 110 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK35-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK35-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×45×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK35-30-TN",
      "NK 35/30 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4906-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4906.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.8,
    "max_rpm": 5600,
    "limiting_speed_rpm": 5600,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4906.2RS is a ribbed machined-ring needle roller bearing (no inner ring) sized 35×47×17 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 35 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 35 mm Fw and 17 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: RNA 4906.2RS shares its 35×47×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 23.3/32 kN ratings and 69 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 4906.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4906.2RS?",
        "a": "A RNA 4906.2RS measures 35 mm bore/Fw × 47 mm outside diameter × 17 mm width (1.378 × 1.85 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 32 kN, fatigue limit Pu 3.8 kN, limiting speed 5,600 r/min, mass about 69 g."
      },
      {
        "q": "How is the RNA 4906.2RS designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 35 mm and width 17 mm, OD 47 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4906.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4906-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×17 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×17 mm envelope, but catalogue C/C0 differ between the executions (23.3/32 vs 25.5/39 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4906-2RS",
      "RNA 4906.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4906",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4906",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.5,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.65,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4906 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 35 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 35 mm Fw and 17 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 69 g at 35×47×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 25.5/39 kN ratings are SKF catalogue values for this exact execution (RNA 4906); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 25.5/39 kN ratings and 69 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RNA 4906 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4906?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4906?",
        "a": "A RNA 4906 measures 35 mm bore/Fw × 47 mm outside diameter × 17 mm width (1.378 × 1.85 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 69 g."
      },
      {
        "q": "How is the RNA 4906 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 35 mm and width 17 mm, OD 47 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4906-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×17 mm envelope, but catalogue C/C0 differ between the executions (25.5/39 vs 23.3/32 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4906",
      "RNA 4906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6906",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6906",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 75,
    "fatigue_load_limit_kN": 9.3,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 6906 in the dimension series 69 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 35 mm bore seat and 47 mm OD. Reading the designation: RNA gives the series and the numbers the boundary plan — 35 mm Fw for the shaft seat, 30 mm width; the 47 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 42.9/75 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 6906 shares its 35×47×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 42.9/75 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RNA 6906 need a hardened and ground shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 6906?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 6906 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 6906 have?",
        "a": "A RNA 6906 measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 75 kN, fatigue limit Pu 9.3 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 130 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6906-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NX35-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX35",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX35-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX35",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR35",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR35-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (42.9/75 vs 24.6/45 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6906",
      "RNA 6906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS35",
    "brand": "SKF",
    "manufacturer_designation": "NKS 35",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 50,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 35.2,
    "static_load_kN": 50,
    "fatigue_load_limit_kN": 6.2,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 35 is a ribbed machined-ring needle roller bearing (no inner ring) sized 35×50×22 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 35 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 35 mm Fw and 22 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 35.2/50 kN ratings are SKF catalogue values for this exact execution (NKS 35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 35.2/50 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKS 35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 35?",
        "a": "A NKS 35 measures 35 mm bore/Fw × 50 mm outside diameter × 22 mm width (1.378 × 1.969 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 35.2 kN, static C0 50 kN, fatigue limit Pu 6.2 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 120 g."
      },
      {
        "q": "How is the NKS 35 designation read?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 35 mm and width 22 mm, OD 50 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NKS 35 run on an unhardened shaft?",
        "a": "No. In this execution the 35 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×50×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS35",
      "NKS 35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK37-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 37/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 37,
    "D_mm": 47,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.1,
    "static_load_kN": 46.5,
    "fatigue_load_limit_kN": 5.85,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 77,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 37/20 is a ribbed machined-ring needle roller bearing (no inner ring) sized 37×47×20 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 37 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 37 mm Fw for the shaft seat, 20 mm width; the 47 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. For life calculation, the 25.1/46.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 47 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 37 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 37 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 25.1/46.5 kN ratings are SKF catalogue values for this exact execution (NK 37/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 25.1/46.5 kN ratings and 77 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 37/20 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 37 mm and width 20 mm, OD 47 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 37/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 37 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 37/20?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 37 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 37/20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK37-20-D-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 37×47×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK37-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 37×47×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK37-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK37",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK37-20",
      "NK 37/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK37-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 37/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 37,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 76.5,
    "fatigue_load_limit_kN": 9.5,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 37/30 designates a flanged, machined outer ring filled with needle rollers and a cage for a 37 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The NK 37/30 code states Fw 37 and width 30 mm directly; because the family has no inner ring, the 37 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. For life calculation, the 36.9/76.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 37 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 37 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 36.9/76.5 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NK 37/30 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 37 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 37/30?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 37 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 37/30?",
        "a": "A NK 37/30 measures 37 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.457 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 36.9 kN, static C0 76.5 kN, fatigue limit Pu 9.5 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 110 g."
      },
      {
        "q": "How is the NK 37/30 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 37 mm and width 30 mm, OD 47 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK37-20-D-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK37-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK37-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 37×47×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK37",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK37-30",
      "NK 37/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS37",
    "brand": "SKF",
    "manufacturer_designation": "NKS 37",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 37,
    "D_mm": 52,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 12000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 12000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's wide-section machined-ring needle roller bearings without inner ring include NKS 37: 37 mm Fw, 52 mm outside diameter, 22 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The NKS 37 code states Fw 37 and width 22 mm directly; because the family has no inner ring, the 37 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 37 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 37 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NKS 37 shares its 37×52×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 10,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 36.9/54 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKS 37 run on an unhardened shaft?",
        "a": "No. In this execution the 37 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NKS 37 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 37 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKS 37?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 37 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 37?",
        "a": "A NKS 37 measures 37 mm bore/Fw × 52 mm outside diameter × 22 mm width (1.457 × 2.047 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 36.9 kN, static C0 54 kN, fatigue limit Pu 6.55 kN, limiting speed 12,000 r/min, reference speed 10,000 r/min, mass about 120 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS37-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 37×52×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS37",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS37",
      "NKS 37"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK38-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 38/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 38,
    "D_mm": 48,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.5,
    "static_load_kN": 49,
    "fatigue_load_limit_kN": 6.1,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 79,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 38/20 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 38 mm bore seat and 48 mm OD. The NK 38/20 code states Fw 38 and width 20 mm directly; because the family has no inner ring, the 38 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. The 79 g catalogue mass and 5.0 mm radial section ((48−38)/2) frame a rating of about 0.67 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 38 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 38 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 25.5/49 kN ratings and 79 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 38/20 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 38 mm and width 20 mm, OD 48 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 38/20 run on an unhardened shaft?",
        "a": "No. In this execution the 38 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 38/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 38 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 38/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 38 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK38-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 38×48×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK38-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK38",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK38-20",
      "NK 38/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK38-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 38/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 38,
    "D_mm": 48,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 37.4,
    "static_load_kN": 80,
    "fatigue_load_limit_kN": 10,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 38/30: 38 mm Fw, 48 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 38 mm under-roller diameter and the 30 mm width, with the 48 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Speed planning separates the two ceilings: 11,000 r/min thermal reference and 12,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 38 mm seat. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 48 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 38 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 38 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 38/30 shares its 38×48×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 37.4/80 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 38/30 need a hardened and ground shaft?",
        "a": "No. In this execution the 38 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 38/30?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 38 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 38/30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 38/30 have?",
        "a": "A NK 38/30 measures 38 mm bore/Fw × 48 mm outside diameter × 30 mm width (1.496 × 1.89 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 37.4 kN, static C0 80 kN, fatigue limit Pu 10 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 120 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK38-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK38-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 38×48×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK38",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK38-30",
      "NK 38/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK40-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 40/20 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 50,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 29.7,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 78,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 40/20 TN in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 40 mm bore seat and 50 mm OD. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 40 mm under-roller diameter and the 20 mm width, with the 50 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 29.7/60 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 29.7/60 kN ratings are SKF catalogue values for this exact execution (NK 40/20 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 29.7/60 kN ratings and 78 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 40/20 TN mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 40 mm and width 20 mm, OD 50 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 40/20 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 40/20 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 40/20 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK40-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×50×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK40-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK40",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK40-20-TN",
      "NK 40/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK40-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 40/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 50,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 83,
    "fatigue_load_limit_kN": 10.4,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 40/30 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 40 mm bore seat and 50 mm OD. The NK 40/30 code states Fw 40 and width 30 mm directly; because the family has no inner ring, the 40 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 130 g at 40×50×30 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 38/83 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 40/30?",
        "a": "A NK 40/30 measures 40 mm bore/Fw × 50 mm outside diameter × 30 mm width (1.575 × 1.969 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 83 kN, fatigue limit Pu 10.4 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 130 g."
      },
      {
        "q": "How is the NK 40/30 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 40 mm and width 30 mm, OD 50 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 40/30 run on an unhardened shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 40/30 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK40-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK40-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×50×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK40",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK40-30",
      "NK 40/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA49-32",
    "brand": "SKF",
    "manufacturer_designation": "RNA 49/32",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 30.8,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 89,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 49/32 designates a flanged, machined outer ring filled with needle rollers and a cage for a 40 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The RNA 49/32 code states Fw 40 and width 20 mm directly; because the family has no inner ring, the 40 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. The 89 g catalogue mass and 6.0 mm radial section ((52−40)/2) frame a rating of about 0.77 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: RNA 49/32 shares its 40×52×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 10,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 30.8/51 kN ratings and 89 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 49/32 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 40 mm and width 20 mm, OD 52 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 49/32 run on an unhardened shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 49/32 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 49/32?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA49-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA49-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA49-32-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA49",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA49-32",
      "RNA 49/32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA69-32",
    "brand": "SKF",
    "manufacturer_designation": "RNA 69/32",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 47.3,
    "static_load_kN": 90,
    "fatigue_load_limit_kN": 10.8,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 69/32 in the dimension series 69 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 40 mm bore seat and 52 mm OD. Reading the designation: RNA gives the series and the numbers the boundary plan — 40 mm Fw for the shaft seat, 36 mm width; the 52 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 47.3/90 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 47.3/90 kN ratings are SKF catalogue values for this exact execution (RNA 69/32); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 47.3/90 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 69/32?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 69/32 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 69/32 have?",
        "a": "A RNA 69/32 measures 40 mm bore/Fw × 52 mm outside diameter × 36 mm width (1.575 × 2.047 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 47.3 kN, static C0 90 kN, fatigue limit Pu 10.8 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 160 g."
      },
      {
        "q": "What does RNA 69/32 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 40 mm and width 36 mm, OD 52 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA69-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA69-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RNA69-32-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA69",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA69-32",
      "RNA 69/32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS40",
    "brand": "SKF",
    "manufacturer_designation": "NKS 40",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 55,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 40 belongs to the machined-ring needle roller family: an outer ring turned and ground to 55 mm with two retaining flanges, a roller-and-cage set inside, and envelope 40×55×22 mm on a hardened 40 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 40 mm Fw and 22 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 38/57 kN ratings are SKF catalogue values for this exact execution (NKS 40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 38/57 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKS 40 designation read?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 40 mm and width 22 mm, OD 55 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NKS 40 run on an unhardened shaft?",
        "a": "No. In this execution the 40 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NKS 40 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKS 40?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS40-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×55×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS40",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS40",
      "NKS 40"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK42-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 42/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 52,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27,
    "static_load_kN": 53,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 86,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 42/20 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 42 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The NK 42/20 code states Fw 42 and width 20 mm directly; because the family has no inner ring, the 42 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 27/53 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NK 42/20 shares its 42×52×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 9,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 27/53 kN ratings and 86 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 42/20 run on an unhardened shaft?",
        "a": "No. In this execution the 42 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 42/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 42 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 42/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 42 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 42/20?",
        "a": "A NK 42/20 measures 42 mm bore/Fw × 52 mm outside diameter × 20 mm width (1.654 × 2.047 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27 kN, static C0 53 kN, fatigue limit Pu 6.55 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 86 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK42-20-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK42-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK42",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK42-20",
      "NK 42/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK42-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 42/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 52,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.1,
    "static_load_kN": 86.5,
    "fatigue_load_limit_kN": 10.8,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 42/30 belongs to the machined-ring needle roller family: an outer ring turned and ground to 52 mm with two retaining flanges, a roller-and-cage set inside, and envelope 42×52×30 mm on a hardened 42 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 42 mm under-roller diameter and the 30 mm width, with the 52 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 39.1/86.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 9,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 42 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 39.1/86.5 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 42/30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 42/30 have?",
        "a": "A NK 42/30 measures 42 mm bore/Fw × 52 mm outside diameter × 30 mm width (1.654 × 2.047 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.1 kN, static C0 86.5 kN, fatigue limit Pu 10.8 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 130 g."
      },
      {
        "q": "What does NK 42/30 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 42 mm and width 30 mm, OD 52 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 42/30 need a hardened and ground shaft?",
        "a": "No. In this execution the 42 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK42-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK42-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 42×52×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK42",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK42-30",
      "NK 42/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4907-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4907.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.3,
    "max_rpm": 4800,
    "limiting_speed_rpm": 4800,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4907.2RS belongs to the machined-ring needle roller family: an outer ring turned and ground to 55 mm with two retaining flanges, a roller-and-cage set inside, and envelope 42×55×20 mm on a hardened 42 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 42 mm Fw and 20 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 4,800 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 42 mm seat. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 27/43 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 4907.2RS?",
        "a": "A RNA 4907.2RS measures 42 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.654 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27 kN, static C0 43 kN, fatigue limit Pu 5.3 kN, limiting speed 4,800 r/min, mass about 110 g."
      },
      {
        "q": "How is the RNA 4907.2RS designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 42 mm and width 20 mm, OD 55 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4907.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 42 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4907.2RS be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 42 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4907-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 42×55×20 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4907",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 42×55×20 mm envelope, but catalogue C/C0 differ between the executions (27/43 vs 31.9/54 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4907-2RS",
      "RNA 4907.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4907",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4907",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.7,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4907: 42 mm Fw, 55 mm outside diameter, 20 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. Reading the designation: RNA gives the series and the numbers the boundary plan — 42 mm Fw for the shaft seat, 20 mm width; the 55 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 110 g at 42×55×20 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 9,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 42 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 31.9/54 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RNA 4907 need a hardened and ground shaft?",
        "a": "No. In this execution the 42 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4907?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 42 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4907 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4907 have?",
        "a": "A RNA 4907 measures 42 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.654 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 54 kN, fatigue limit Pu 6.7 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 110 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4907-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 42×55×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 42×55×20 mm envelope, but catalogue C/C0 differ between the executions (31.9/54 vs 27/43 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4907",
      "RNA 4907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6907",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6907",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 55,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 48.4,
    "static_load_kN": 93,
    "fatigue_load_limit_kN": 11.4,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6907 is a ribbed machined-ring needle roller bearing (no inner ring) sized 42×55×36 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 42 mm shaft journal completes the bearing. The RNA 6907 code states Fw 42 and width 36 mm directly; because the family has no inner ring, the 42 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 48.4/93 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 48.4/93 kN ratings and 190 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 6907 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 42 mm and width 36 mm, OD 55 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 6907 run on an unhardened shaft?",
        "a": "No. In this execution the 42 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 6907 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 42 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 6907?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 42 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6907-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 42×55×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6907",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6907",
      "RNA 6907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK43-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 43/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 43,
    "D_mm": 53,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 55,
    "fatigue_load_limit_kN": 6.8,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 86,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 43/20 is a ribbed machined-ring needle roller bearing (no inner ring) sized 43×53×20 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 43 mm shaft journal completes the bearing. The NK 43/20 code states Fw 43 and width 20 mm directly; because the family has no inner ring, the 43 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 27.5/55 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 43 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 43 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 43 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 27.5/55 kN ratings are SKF catalogue values for this exact execution (NK 43/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 27.5/55 kN ratings and 86 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 43/20 run on an unhardened shaft?",
        "a": "No. In this execution the 43 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 43/20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 43 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 43/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 43 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 43/20?",
        "a": "A NK 43/20 measures 43 mm bore/Fw × 53 mm outside diameter × 20 mm width (1.693 × 2.087 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 55 kN, fatigue limit Pu 6.8 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 86 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK43-20-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NK43-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK43",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK43-20",
      "NK 43/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK43-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 43/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 43,
    "D_mm": 53,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 90,
    "fatigue_load_limit_kN": 11.2,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 43/30 designates a flanged, machined outer ring filled with needle rollers and a cage for a 43 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 43 mm under-roller diameter and the 30 mm width, with the 53 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 40.2/90 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 53 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 43 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 43 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 40.2/90 kN ratings are SKF catalogue values for this exact execution (NK 43/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 40.2/90 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 43/30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 43/30 have?",
        "a": "A NK 43/30 measures 43 mm bore/Fw × 53 mm outside diameter × 30 mm width (1.693 × 2.087 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 40.2 kN, static C0 90 kN, fatigue limit Pu 11.2 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 130 g."
      },
      {
        "q": "What does NK 43/30 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 43 mm and width 30 mm, OD 53 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 43/30 need a hardened and ground shaft?",
        "a": "No. In this execution the 43 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK43-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK43-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 43×53×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK43",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK43-30",
      "NK 43/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS43",
    "brand": "SKF",
    "manufacturer_designation": "NKS 43",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 43,
    "D_mm": 58,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.1,
    "static_load_kN": 61,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 43 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 43 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NKS families drop the inner ring: the numbers after the letters give the 43 mm under-roller diameter and the 22 mm width, with the 58 mm outside diameter set by the wide-section machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 43 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 43 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKS 43 shares its 43×58×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 39.1/61 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 630); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKS 43?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 43 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKS 43 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKS 43 have?",
        "a": "A NKS 43 measures 43 mm bore/Fw × 58 mm outside diameter × 22 mm width (1.693 × 2.283 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.1 kN, static C0 61 kN, fatigue limit Pu 7.5 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 140 g."
      },
      {
        "q": "What does NKS 43 mean in SKF part numbering?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 43 mm and width 22 mm, OD 58 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS43-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 43×58×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS43",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS43",
      "NKS 43"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK45-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 45/20 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 31.4,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 85,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 45/20 TN belongs to the machined-ring needle roller family: an outer ring turned and ground to 55 mm with two retaining flanges, a roller-and-cage set inside, and envelope 45×55×20 mm on a hardened 45 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 45 mm under-roller diameter and the 20 mm width, with the 55 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 45/20 TN shares its 45×55×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 31.4/65.5 kN ratings and 85 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 45/20 TN mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 45 mm and width 20 mm, OD 55 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 45/20 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 45/20 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 45/20 TN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK45-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×55×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK45-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK45-20-TN",
      "NK 45/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK45-30-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 45/30 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 55,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 45.7,
    "static_load_kN": 108,
    "fatigue_load_limit_kN": 13.7,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 45/30 TN: 45 mm Fw, 55 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The NK 45/30 TN code states Fw 45 and width 30 mm directly; because the family has no inner ring, the 45 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. The 130 g catalogue mass and 5.0 mm radial section ((55−45)/2) frame a rating of about 1.02 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 45.7/108 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 45/30 TN run on an unhardened shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 45/30 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 45/30 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 45/30 TN?",
        "a": "A NK 45/30 TN measures 45 mm bore/Fw × 55 mm outside diameter × 30 mm width (1.772 × 2.165 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 45.7 kN, static C0 108 kN, fatigue limit Pu 13.7 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 130 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK45-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK45-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×55×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK45-30-TN",
      "NK 45/30 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS45",
    "brand": "SKF",
    "manufacturer_designation": "NKS 45",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 60,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 64,
    "fatigue_load_limit_kN": 8,
    "max_rpm": 10000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 10000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKS 45 designates a flanged, machined outer ring filled with needle rollers and a cage for a 45 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. Reading the designation: NKS gives the series and the numbers the boundary plan — 45 mm Fw for the shaft seat, 22 mm width; the 60 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 40.2/64 kN ratings are SKF catalogue values for this exact execution (NKS 45); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 40.2/64 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKS 45 mean in SKF part numbering?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 45 mm and width 22 mm, OD 60 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NKS 45 need a hardened and ground shaft?",
        "a": "No. In this execution the 45 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NKS 45?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKS 45 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS45-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×60×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS45",
      "NKS 45"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK47-20",
    "brand": "SKF",
    "manufacturer_designation": "NK 47/20",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 47,
    "D_mm": 57,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 29.2,
    "static_load_kN": 61,
    "fatigue_load_limit_kN": 7.65,
    "max_rpm": 10000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 10000,
    "weight_g": 95,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 47/20 belongs to the machined-ring needle roller family: an outer ring turned and ground to 57 mm with two retaining flanges, a roller-and-cage set inside, and envelope 47×57×20 mm on a hardened 47 mm shaft. Reading the designation: NK gives the series and the numbers the boundary plan — 47 mm Fw for the shaft seat, 20 mm width; the 57 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Selection arithmetic: C 29.2 kN against C0 61 kN gives a C0/C ratio of 2.09, and the 7.65 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 47 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 47 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 8,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 47 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 29.2/61 kN ratings and 95 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 47/20 need a hardened and ground shaft?",
        "a": "No. In this execution the 47 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 47/20?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 47 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 47/20 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 47/20 have?",
        "a": "A NK 47/20 measures 47 mm bore/Fw × 57 mm outside diameter × 20 mm width (1.85 × 2.244 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 29.2 kN, static C0 61 kN, fatigue limit Pu 7.65 kN, limiting speed 10,000 r/min, reference speed 8,500 r/min, mass about 95 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK47-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 47×57×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK47-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK47",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK47-20",
      "NK 47/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK47-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 47/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 47,
    "D_mm": 57,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 41.8,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.5,
    "max_rpm": 10000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 10000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 47/30 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 47 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The NK 47/30 code states Fw 47 and width 30 mm directly; because the family has no inner ring, the 47 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Selection arithmetic: C 41.8 kN against C0 98 kN gives a C0/C ratio of 2.34, and the 12.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 57 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 47 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 47 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 47 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 41.8/98 kN ratings are SKF catalogue values for this exact execution (NK 47/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 41.8/98 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NK 47/30?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 47 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 47/30?",
        "a": "A NK 47/30 measures 47 mm bore/Fw × 57 mm outside diameter × 30 mm width (1.85 × 2.244 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 41.8 kN, static C0 98 kN, fatigue limit Pu 12.5 kN, limiting speed 10,000 r/min, reference speed 8,500 r/min, mass about 140 g."
      },
      {
        "q": "How is the NK 47/30 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 47 mm and width 30 mm, OD 57 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 47/30 run on an unhardened shaft?",
        "a": "No. In this execution the 47 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK47-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK47-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 47×57×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK47",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK47-30",
      "NK 47/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4908-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4908.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 48,
    "D_mm": 62,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 58.5,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 4000,
    "limiting_speed_rpm": 4000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4908.2RS: 48 mm Fw, 62 mm outside diameter, 22 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 48 mm under-roller diameter and the 22 mm width, with the 62 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Catalogue mass 150 g at 48×62×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 62 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 48 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 48 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 36.9/58.5 kN ratings are SKF catalogue values for this exact execution (RNA 4908.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 36.9/58.5 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 4908.2RS mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 48 mm and width 22 mm, OD 62 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4908.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 48 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4908.2RS?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 48 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4908.2RS sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4908-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 48×62×22 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4908",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 48×62×22 mm envelope, but catalogue C/C0 differ between the executions (36.9/58.5 vs 42.9/71 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4908-2RS",
      "RNA 4908.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4908",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4908",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 48,
    "D_mm": 62,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 71,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4908 designates a flanged, machined outer ring filled with needle rollers and a cage for a 48 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The RNA 4908 code states Fw 48 and width 22 mm directly; because the family has no inner ring, the 48 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 140 g at 48×62×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 48 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 48 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: RNA 4908 shares its 48×62×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 42.9/71 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 4908 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 48 mm and width 22 mm, OD 62 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4908 run on an unhardened shaft?",
        "a": "No. In this execution the 48 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4908 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 48 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4908?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 48 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4908-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 48×62×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 48×62×22 mm envelope, but catalogue C/C0 differ between the executions (42.9/71 vs 36.9/58.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4908",
      "RNA 4908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6908",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6908",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 48,
    "D_mm": 62,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 67.1,
    "static_load_kN": 125,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6908 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 48 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 48 mm under-roller diameter and the 40 mm width, with the 62 mm outside diameter set by the dimension series 69 needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 67.1/125 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 48 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 48 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 67.1/125 kN ratings are SKF catalogue values for this exact execution (RNA 6908); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 67.1/125 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 6908 have?",
        "a": "A RNA 6908 measures 48 mm bore/Fw × 62 mm outside diameter × 40 mm width (1.89 × 2.441 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 67.1 kN, static C0 125 kN, fatigue limit Pu 15.3 kN, limiting speed 9,500 r/min, reference speed 8,000 r/min, mass about 260 g."
      },
      {
        "q": "What does RNA 6908 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 48 mm and width 40 mm, OD 62 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 6908 need a hardened and ground shaft?",
        "a": "No. In this execution the 48 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 6908?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 48 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6908-ZW-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "RNA6908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6908",
      "RNA 6908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK50-25-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 50/25 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 62,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 91.5,
    "fatigue_load_limit_kN": 11.2,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 50/25 TN: 50 mm Fw, 62 mm outside diameter, 25 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 50 mm Fw and 25 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 42.9/91.5 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 50/25 TN?",
        "a": "A NK 50/25 TN measures 50 mm bore/Fw × 62 mm outside diameter × 25 mm width (1.969 × 2.441 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 91.5 kN, fatigue limit Pu 11.2 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 150 g."
      },
      {
        "q": "How is the NK 50/25 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 50 mm and width 25 mm, OD 62 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 50/25 TN run on an unhardened shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 50/25 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK50-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×62×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK50-35-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK50",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK50-25-TN",
      "NK 50/25 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK50-35-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 50/35 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 62,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 58.3,
    "static_load_kN": 137,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 210,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 50/35 TN is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 50 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 50 mm Fw and 35 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Speed planning separates the two ceilings: 8,000 r/min thermal reference and 9,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 50 mm seat. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 58.3/137 kN ratings are SKF catalogue values for this exact execution (NK 50/35 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 58.3/137 kN ratings and 210 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 50/35 TN designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 50 mm and width 35 mm, OD 62 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 50/35 TN run on an unhardened shaft?",
        "a": "No. In this execution the 50 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 50/35 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 50/35 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK50-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK50-35-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKX50-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (58.3/137 vs 38/78 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX50",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (58.3/137 vs 38/78 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR50",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (58.3/137 vs 38/78 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR50-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (58.3/137 vs 38/78 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK50-35-TN",
      "NK 50/35 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS50",
    "brand": "SKF",
    "manufacturer_designation": "NKS 50",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 65,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 72,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 50 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 50 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: NKS gives the series and the numbers the boundary plan — 50 mm Fw for the shaft seat, 22 mm width; the 65 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 65 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 42.9/72 kN ratings are SKF catalogue values for this exact execution (NKS 50); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 42.9/72 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKS 50?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKS 50 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKS 50 have?",
        "a": "A NKS 50 measures 50 mm bore/Fw × 65 mm outside diameter × 22 mm width (1.969 × 2.559 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 72 kN, fatigue limit Pu 8.8 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 160 g."
      },
      {
        "q": "What does NKS 50 mean in SKF part numbering?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 50 mm and width 22 mm, OD 65 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS50-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×65×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS50",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS50",
      "NKS 50"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4909-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4909.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 52,
    "D_mm": 68,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.1,
    "static_load_kN": 64,
    "fatigue_load_limit_kN": 7.8,
    "max_rpm": 3800,
    "limiting_speed_rpm": 3800,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4909.2RS is a ribbed machined-ring needle roller bearing (no inner ring) sized 52×68×22 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 52 mm shaft journal completes the bearing. The RNA 4909.2RS code states Fw 52 and width 22 mm directly; because the family has no inner ring, the 52 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 39.1/64 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 52 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 52 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 39.1/64 kN ratings are SKF catalogue values for this exact execution (RNA 4909.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 39.1/64 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 4909.2RS run on an unhardened shaft?",
        "a": "No. In this execution the 52 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4909.2RS be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 52 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4909.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 52 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4909.2RS?",
        "a": "A RNA 4909.2RS measures 52 mm bore/Fw × 68 mm outside diameter × 22 mm width (2.047 × 2.677 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.1 kN, static C0 64 kN, fatigue limit Pu 7.8 kN, limiting speed 3,800 r/min, mass about 160 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4909-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 52×68×22 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4909",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 52×68×22 mm envelope, but catalogue C/C0 differ between the executions (39.1/64 vs 45.7/78 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4909-2RS",
      "RNA 4909.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4909",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4909",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 52,
    "D_mm": 68,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 45.7,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4909 belongs to the machined-ring needle roller family: an outer ring turned and ground to 68 mm with two retaining flanges, a roller-and-cage set inside, and envelope 52×68×22 mm on a hardened 52 mm shaft. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 52 mm under-roller diameter and the 22 mm width, with the 68 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 180 g at 52×68×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 52 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4909 shares its 52×68×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 45.7/78 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 4909 have?",
        "a": "A RNA 4909 measures 52 mm bore/Fw × 68 mm outside diameter × 22 mm width (2.047 × 2.677 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 45.7 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 180 g."
      },
      {
        "q": "What does RNA 4909 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 52 mm and width 22 mm, OD 68 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4909 need a hardened and ground shaft?",
        "a": "No. In this execution the 52 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4909?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 52 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4909-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 52×68×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 52×68×22 mm envelope, but catalogue C/C0 differ between the executions (45.7/78 vs 39.1/64 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4909",
      "RNA 4909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6909",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6909",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 52,
    "D_mm": 68,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 70.4,
    "static_load_kN": 137,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 69 needle roller bearings without inner ring include RNA 6909: 52 mm Fw, 68 mm outside diameter, 40 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 52 mm Fw and 40 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 70.4/137 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 52 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 52 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 70.4/137 kN ratings are SKF catalogue values for this exact execution (RNA 6909); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 70.4/137 kN ratings and 340 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 6909?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 52 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 6909?",
        "a": "A RNA 6909 measures 52 mm bore/Fw × 68 mm outside diameter × 40 mm width (2.047 × 2.677 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 70.4 kN, static C0 137 kN, fatigue limit Pu 17 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 340 g."
      },
      {
        "q": "How is the RNA 6909 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 52 mm and width 40 mm, OD 68 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 6909 run on an unhardened shaft?",
        "a": "No. In this execution the 52 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6909-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 52×68×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6909",
      "RNA 6909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK55-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 55/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 68,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 88,
    "fatigue_load_limit_kN": 10.8,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 55/25: 55 mm Fw, 68 mm outside diameter, 25 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 55 mm Fw and 25 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Catalogue mass 180 g at 55×68×25 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 40.2/88 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NK 55/25 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 55 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 55/25?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 55/25?",
        "a": "A NK 55/25 measures 55 mm bore/Fw × 68 mm outside diameter × 25 mm width (2.165 × 2.677 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 40.2 kN, static C0 88 kN, fatigue limit Pu 10.8 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 180 g."
      },
      {
        "q": "How is the NK 55/25 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 55 mm and width 25 mm, OD 68 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK55-25-D-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×68×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK55-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×68×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK55-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK55",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK55-25",
      "NK 55/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK55-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 55/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 68,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 52.3,
    "static_load_kN": 122,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 55/35 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 55 mm bore seat and 68 mm OD. Reading the designation: NK gives the series and the numbers the boundary plan — 55 mm Fw for the shaft seat, 35 mm width; the 68 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Catalogue mass 250 g at 55×68×35 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 55/35 shares its 55×68×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 52.3/122 kN ratings and 250 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NK 55/35 have?",
        "a": "A NK 55/35 measures 55 mm bore/Fw × 68 mm outside diameter × 35 mm width (2.165 × 2.677 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 52.3 kN, static C0 122 kN, fatigue limit Pu 15.3 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 250 g."
      },
      {
        "q": "What does NK 55/35 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 55 mm and width 35 mm, OD 68 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 55/35 need a hardened and ground shaft?",
        "a": "No. In this execution the 55 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 55/35?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 55 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK55-25-D-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK55-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK55-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×68×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK55",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK55-35",
      "NK 55/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS55",
    "brand": "SKF",
    "manufacturer_designation": "NKS 55",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44.6,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.8,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 55 is a ribbed machined-ring needle roller bearing (no inner ring) sized 55×72×22 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 55 mm shaft journal completes the bearing. The NKS 55 code states Fw 55 and width 22 mm directly; because the family has no inner ring, the 55 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 72 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 44.6/78 kN ratings and 220 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKS 55 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 55 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKS 55?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 55?",
        "a": "A NKS 55 measures 55 mm bore/Fw × 72 mm outside diameter × 22 mm width (2.165 × 2.835 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44.6 kN, static C0 78 kN, fatigue limit Pu 9.8 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 220 g."
      },
      {
        "q": "How is the NKS 55 designation read?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 55 mm and width 22 mm, OD 72 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS55-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×72×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS55",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS55",
      "NKS 55"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4910-2RS",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4910.2RS",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 58,
    "D_mm": 72,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 69.5,
    "fatigue_load_limit_kN": 8.5,
    "max_rpm": 3400,
    "limiting_speed_rpm": 3400,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4910.2RS: 58 mm Fw, 72 mm outside diameter, 22 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 58 mm under-roller diameter and the 22 mm width, with the 72 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 160 g at 58×72×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 58 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4910.2RS shares its 58×72×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 40.2/69.5 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 4910.2RS mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 58 mm and width 22 mm, OD 72 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4910.2RS need a hardened and ground shaft?",
        "a": "No. In this execution the 58 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4910.2RS?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 58 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4910.2RS sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4910-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 58×72×22 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "RNA4910",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 58×72×22 mm envelope, but catalogue C/C0 differ between the executions (40.2/69.5 vs 47.3/85 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4910-2RS",
      "RNA 4910.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4910",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4910",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 58,
    "D_mm": 72,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 47.3,
    "static_load_kN": 85,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4910 belongs to the machined-ring needle roller family: an outer ring turned and ground to 72 mm with two retaining flanges, a roller-and-cage set inside, and envelope 58×72×22 mm on a hardened 58 mm shaft. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 58 mm under-roller diameter and the 22 mm width, with the 72 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 160 g at 58×72×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 58 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 47.3/85 kN ratings are SKF catalogue values for this exact execution (RNA 4910); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 47.3/85 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 4910 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 58 mm and width 22 mm, OD 72 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4910 need a hardened and ground shaft?",
        "a": "No. In this execution the 58 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4910?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 58 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4910 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4910-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 58×72×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4910-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 58×72×22 mm envelope, but catalogue C/C0 differ between the executions (47.3/85 vs 40.2/69.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4910",
      "RNA 4910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6910",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6910",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 58,
    "D_mm": 72,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 73.7,
    "static_load_kN": 150,
    "fatigue_load_limit_kN": 18.6,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 69 needle roller bearings without inner ring include RNA 6910: 58 mm Fw, 72 mm outside diameter, 40 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 58 mm Fw and 40 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 73.7/150 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 58 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 6910 shares its 58×72×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 7,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 73.7/150 kN ratings and 310 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 6910?",
        "a": "A RNA 6910 measures 58 mm bore/Fw × 72 mm outside diameter × 40 mm width (2.283 × 2.835 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 73.7 kN, static C0 150 kN, fatigue limit Pu 18.6 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 310 g."
      },
      {
        "q": "How is the RNA 6910 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 58 mm and width 40 mm, OD 72 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 6910 run on an unhardened shaft?",
        "a": "No. In this execution the 58 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 6910 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 58 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6910-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 58×72×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6910",
      "RNA 6910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK60-25-TN",
    "brand": "SKF",
    "manufacturer_designation": "NK 60/25 TN",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 72,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 46.8,
    "static_load_kN": 110,
    "fatigue_load_limit_kN": 13.4,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 60/25 TN designates a flanged, machined outer ring filled with needle rollers and a cage for a 60 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 60 mm under-roller diameter and the 25 mm width, with the 72 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. The 170 g catalogue mass and 6.0 mm radial section ((72−60)/2) frame a rating of about 0.78 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 46.8/110 kN ratings are SKF catalogue values for this exact execution (NK 60/25 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 46.8/110 kN ratings and 170 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NK 60/25 TN have?",
        "a": "A NK 60/25 TN measures 60 mm bore/Fw × 72 mm outside diameter × 25 mm width (2.362 × 2.835 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 46.8 kN, static C0 110 kN, fatigue limit Pu 13.4 kN, limiting speed 7,500 r/min, reference speed 6,700 r/min, mass about 170 g."
      },
      {
        "q": "What does NK 60/25 TN mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 60 mm and width 25 mm, OD 72 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 60/25 TN need a hardened and ground shaft?",
        "a": "No. In this execution the 60 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 60/25 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK60-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×72×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK60-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK60",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK60-25-TN",
      "NK 60/25 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK60-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 60/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 72,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 55,
    "static_load_kN": 134,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 60/35 is a ribbed machined-ring needle roller bearing (no inner ring) sized 60×72×35 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 60 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 60 mm Fw for the shaft seat, 35 mm width; the 72 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Speed planning separates the two ceilings: 6,700 r/min thermal reference and 7,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 60 mm seat. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 55/134 kN ratings are SKF catalogue values for this exact execution (NK 60/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 55/134 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 60/35 need a hardened and ground shaft?",
        "a": "No. In this execution the 60 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 60/35?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 60/35 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 60/35 have?",
        "a": "A NK 60/35 measures 60 mm bore/Fw × 72 mm outside diameter × 35 mm width (2.362 × 2.835 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 55 kN, static C0 134 kN, fatigue limit Pu 17 kN, limiting speed 7,500 r/min, reference speed 6,700 r/min, mass about 260 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK60-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK60-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×72×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK60",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK60-35",
      "NK 60/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS60",
    "brand": "SKF",
    "manufacturer_designation": "NKS 60",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 80,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 62.7,
    "static_load_kN": 104,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 7500,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7500,
    "weight_g": 340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 60 belongs to the machined-ring needle roller family: an outer ring turned and ground to 80 mm with two retaining flanges, a roller-and-cage set inside, and envelope 60×80×28 mm on a hardened 60 mm shaft. The NKS 60 code states Fw 60 and width 28 mm directly; because the family has no inner ring, the 60 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 62.7/104 kN ratings and 340 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKS 60?",
        "a": "A NKS 60 measures 60 mm bore/Fw × 80 mm outside diameter × 28 mm width (2.362 × 3.15 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 62.7 kN, static C0 104 kN, fatigue limit Pu 13.2 kN, limiting speed 7,500 r/min, reference speed 6,300 r/min, mass about 340 g."
      },
      {
        "q": "How is the NKS 60 designation read?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 60 mm and width 28 mm, OD 80 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NKS 60 run on an unhardened shaft?",
        "a": "No. In this execution the 60 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NKS 60 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS60-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×80×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS60",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS60",
      "NKS 60"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4911",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4911",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 63,
    "D_mm": 80,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 57.2,
    "static_load_kN": 106,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 4911 in the dimension series 49 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 63 mm bore seat and 80 mm OD. The letters identify a flanged machined outer ring without inner ring; the figures give 63 mm Fw and 25 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 260 g at 63×80×25 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 63 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 63 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 57.2/106 kN ratings are SKF catalogue values for this exact execution (RNA 4911); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 57.2/106 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 4911?",
        "a": "A RNA 4911 measures 63 mm bore/Fw × 80 mm outside diameter × 25 mm width (2.48 × 3.15 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 57.2 kN, static C0 106 kN, fatigue limit Pu 13.2 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 260 g."
      },
      {
        "q": "How is the RNA 4911 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 63 mm and width 25 mm, OD 80 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4911 run on an unhardened shaft?",
        "a": "No. In this execution the 63 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4911 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 63 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4911-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 63×80×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4911",
      "RNA 4911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6911",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6911",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 63,
    "D_mm": 80,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 89.7,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 23.2,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 470,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 6911 designates a flanged, machined outer ring filled with needle rollers and a cage for a 63 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. Reading the designation: RNA gives the series and the numbers the boundary plan — 63 mm Fw for the shaft seat, 45 mm width; the 80 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 89.7/190 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 63 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 6911 shares its 63×80×45 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 89.7/190 kN ratings and 470 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the RNA 6911 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 6911 have?",
        "a": "A RNA 6911 measures 63 mm bore/Fw × 80 mm outside diameter × 45 mm width (2.48 × 3.15 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 89.7 kN, static C0 190 kN, fatigue limit Pu 23.2 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 470 g."
      },
      {
        "q": "What does RNA 6911 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 63 mm and width 45 mm, OD 80 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 6911 need a hardened and ground shaft?",
        "a": "No. In this execution the 63 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6911-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 63×80×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6911",
      "RNA 6911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK65-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 65/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 78,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44,
    "static_load_kN": 104,
    "fatigue_load_limit_kN": 12.7,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 65/25 is a ribbed machined-ring needle roller bearing (no inner ring) sized 65×78×25 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 65 mm shaft journal completes the bearing. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 65 mm under-roller diameter and the 25 mm width, with the 78 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. For life calculation, the 44/104 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 78 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 44/104 kN ratings are SKF catalogue values for this exact execution (NK 65/25); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 44/104 kN ratings and 220 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 65/25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 65/25 have?",
        "a": "A NK 65/25 measures 65 mm bore/Fw × 78 mm outside diameter × 25 mm width (2.559 × 3.071 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44 kN, static C0 104 kN, fatigue limit Pu 12.7 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 220 g."
      },
      {
        "q": "What does NK 65/25 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 65 mm and width 25 mm, OD 78 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 65/25 need a hardened and ground shaft?",
        "a": "No. In this execution the 65 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK65-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×78×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK65-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK65",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK65-25",
      "NK 65/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK65-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 65/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 78,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 58.3,
    "static_load_kN": 146,
    "fatigue_load_limit_kN": 18.3,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 65/35 designates a flanged, machined outer ring filled with needle rollers and a cage for a 65 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 65 mm Fw and 35 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. For life calculation, the 58.3/146 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 58.3/146 kN ratings and 310 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NK 65/35 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 65 mm and width 35 mm, OD 78 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 65/35 run on an unhardened shaft?",
        "a": "No. In this execution the 65 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 65/35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 65 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 65/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 65 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK65-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK65-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×78×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK65",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK65-35",
      "NK 65/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS65",
    "brand": "SKF",
    "manufacturer_designation": "NKS 65",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 85,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 66,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 14.6,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKS 65 designates a flanged, machined outer ring filled with needle rollers and a cage for a 65 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NKS families drop the inner ring: the numbers after the letters give the 65 mm under-roller diameter and the 28 mm width, with the 85 mm outside diameter set by the wide-section machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKS 65 shares its 65×85×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 66/114 kN ratings and 360 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKS 65 have?",
        "a": "A NKS 65 measures 65 mm bore/Fw × 85 mm outside diameter × 28 mm width (2.559 × 3.346 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 66 kN, static C0 114 kN, fatigue limit Pu 14.6 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 360 g."
      },
      {
        "q": "What does NKS 65 mean in SKF part numbering?",
        "a": "NKS names a machined-ring needle roller bearing without inner ring: the figures give Fw 65 mm and width 28 mm, OD 85 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NKS 65 need a hardened and ground shaft?",
        "a": "No. In this execution the 65 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NKS 65?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 65 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS65-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×85×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS65",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS65",
      "NKS 65"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK68-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 68/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 68,
    "D_mm": 82,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44,
    "static_load_kN": 95,
    "fatigue_load_limit_kN": 11.8,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 240,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 68/25 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 68 mm bore seat and 82 mm OD. Reading the designation: NK gives the series and the numbers the boundary plan — 68 mm Fw for the shaft seat, 25 mm width; the 82 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Selection arithmetic: C 44 kN against C0 95 kN gives a C0/C ratio of 2.16, and the 11.8 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 82 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 68 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 68 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 44/95 kN ratings and 240 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NK 68/25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 68 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 68/25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 68/25 have?",
        "a": "A NK 68/25 measures 68 mm bore/Fw × 82 mm outside diameter × 25 mm width (2.677 × 3.228 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44 kN, static C0 95 kN, fatigue limit Pu 11.8 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 240 g."
      },
      {
        "q": "What does NK 68/25 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 68 mm and width 25 mm, OD 82 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK68-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 68×82×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK68-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK68",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK68-25",
      "NK 68/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK68-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 68/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 68,
    "D_mm": 82,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 146,
    "fatigue_load_limit_kN": 18.3,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 68/35: 68 mm Fw, 82 mm outside diameter, 35 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The NK 68/35 code states Fw 68 and width 35 mm directly; because the family has no inner ring, the 68 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Selection arithmetic: C 60.5 kN against C0 146 kN gives a C0/C ratio of 2.41, and the 18.3 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 68 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 68 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 60.5/146 kN ratings are SKF catalogue values for this exact execution (NK 68/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 60.5/146 kN ratings and 340 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 68/35?",
        "a": "A NK 68/35 measures 68 mm bore/Fw × 82 mm outside diameter × 35 mm width (2.677 × 3.228 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 60.5 kN, static C0 146 kN, fatigue limit Pu 18.3 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 340 g."
      },
      {
        "q": "How is the NK 68/35 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 68 mm and width 35 mm, OD 82 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 68/35 run on an unhardened shaft?",
        "a": "No. In this execution the 68 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 68/35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 68 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK68-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK68-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 68×82×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK68",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK68-35",
      "NK 68/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4912",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4912",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 68,
    "D_mm": 85,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 14.3,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 280,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4912 is a ribbed machined-ring needle roller bearing (no inner ring) sized 68×85×25 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 68 mm shaft journal completes the bearing. Reading the designation: RNA gives the series and the numbers the boundary plan — 68 mm Fw for the shaft seat, 25 mm width; the 85 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 280 g at 68×85×25 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 68 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 68 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 60.5/114 kN ratings and 280 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the RNA 4912 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4912 have?",
        "a": "A RNA 4912 measures 68 mm bore/Fw × 85 mm outside diameter × 25 mm width (2.677 × 3.346 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 60.5 kN, static C0 114 kN, fatigue limit Pu 14.3 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 280 g."
      },
      {
        "q": "What does RNA 4912 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 68 mm and width 25 mm, OD 85 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4912 need a hardened and ground shaft?",
        "a": "No. In this execution the 68 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4912-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 68×85×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4912",
      "RNA 4912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6912",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6912",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 68,
    "D_mm": 85,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 93.5,
    "static_load_kN": 204,
    "fatigue_load_limit_kN": 25,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 490,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6912 belongs to the machined-ring needle roller family: an outer ring turned and ground to 85 mm with two retaining flanges, a roller-and-cage set inside, and envelope 68×85×45 mm on a hardened 68 mm shaft. The RNA 6912 code states Fw 68 and width 45 mm directly; because the family has no inner ring, the 68 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 93.5/204 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 68 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 93.5/204 kN ratings and 490 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RNA 6912 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 68 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 6912?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 68 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 6912?",
        "a": "A RNA 6912 measures 68 mm bore/Fw × 85 mm outside diameter × 45 mm width (2.677 × 3.346 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 93.5 kN, static C0 204 kN, fatigue limit Pu 25 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 490 g."
      },
      {
        "q": "How is the RNA 6912 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 68 mm and width 45 mm, OD 85 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6912-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 68×85×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6912",
      "RNA 6912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK70-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 70/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 85,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44.6,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.2,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 70/25: 70 mm Fw, 85 mm outside diameter, 25 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 70 mm Fw and 25 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 44.6/98 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NK 70/25 shares its 70×85×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 44.6/98 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 70/25?",
        "a": "A NK 70/25 measures 70 mm bore/Fw × 85 mm outside diameter × 25 mm width (2.756 × 3.346 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44.6 kN, static C0 98 kN, fatigue limit Pu 12.2 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 260 g."
      },
      {
        "q": "How is the NK 70/25 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 70 mm and width 25 mm, OD 85 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 70/25 run on an unhardened shaft?",
        "a": "No. In this execution the 70 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 70/25 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 70 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK70-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×85×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK70-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK70",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK70-25",
      "NK 70/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK70-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 70/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 85,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 61.6,
    "static_load_kN": 150,
    "fatigue_load_limit_kN": 19,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 70/35 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 70 mm bore seat and 85 mm OD. Reading the designation: NK gives the series and the numbers the boundary plan — 70 mm Fw for the shaft seat, 35 mm width; the 85 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. For life calculation, the 61.6/150 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 85 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 70 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 61.6/150 kN ratings and 370 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 70/35 need a hardened and ground shaft?",
        "a": "No. In this execution the 70 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 70/35?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 70 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 70/35 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 70/35 have?",
        "a": "A NK 70/35 measures 70 mm bore/Fw × 85 mm outside diameter × 35 mm width (2.756 × 3.346 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 61.6 kN, static C0 150 kN, fatigue limit Pu 19 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 370 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK70-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK70-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×85×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK70",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK70-35",
      "NK 70/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS70",
    "brand": "SKF",
    "manufacturer_designation": "NKS 70",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 90,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 68.2,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 70 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 70 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NKS families drop the inner ring: the numbers after the letters give the 70 mm under-roller diameter and the 28 mm width, with the 90 mm outside diameter set by the wide-section machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKS 70 shares its 70×90×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 68.2/120 kN ratings and 380 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 632); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKS 70 need a hardened and ground shaft?",
        "a": "No. In this execution the 70 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NKS 70?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 70 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKS 70 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKS 70 have?",
        "a": "A NKS 70 measures 70 mm bore/Fw × 90 mm outside diameter × 28 mm width (2.756 × 3.543 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 68.2 kN, static C0 120 kN, fatigue limit Pu 15.3 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 380 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS70-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×90×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS70",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS70",
      "NKS 70"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4913",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4913",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 72,
    "D_mm": 90,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 61.6,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 14.6,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4913 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 72 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The RNA 4913 code states Fw 72 and width 25 mm directly; because the family has no inner ring, the 72 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 310 g at 72×90×25 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 72 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 4913 shares its 72×90×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 61.6/120 kN ratings and 310 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RNA 4913 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 72 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4913?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 72 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 9.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4913?",
        "a": "A RNA 4913 measures 72 mm bore/Fw × 90 mm outside diameter × 25 mm width (2.835 × 3.543 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 61.6 kN, static C0 120 kN, fatigue limit Pu 14.6 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 310 g."
      },
      {
        "q": "How is the RNA 4913 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 72 mm and width 25 mm, OD 90 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4913-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 72×90×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4913",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4913",
      "RNA 4913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6913",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6913",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 72,
    "D_mm": 90,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 95.2,
    "static_load_kN": 212,
    "fatigue_load_limit_kN": 26,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 580,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 6913 in the dimension series 69 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 72 mm bore seat and 90 mm OD. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 72 mm under-roller diameter and the 45 mm width, with the 90 mm outside diameter set by the dimension series 69 needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 95.2/212 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 72 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 95.2/212 kN ratings are SKF catalogue values for this exact execution (RNA 6913); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 95.2/212 kN ratings and 580 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RNA 6913 need a hardened and ground shaft?",
        "a": "No. In this execution the 72 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 6913?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 72 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 6913 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 6913 have?",
        "a": "A RNA 6913 measures 72 mm bore/Fw × 90 mm outside diameter × 45 mm width (2.835 × 3.543 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 95.2 kN, static C0 212 kN, fatigue limit Pu 26 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 580 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6913-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 72×90×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6913",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6913",
      "RNA 6913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK73-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 73/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 73,
    "D_mm": 90,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 52.8,
    "static_load_kN": 106,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 73/25 is a ribbed machined-ring needle roller bearing (no inner ring) sized 73×90×25 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 73 mm shaft journal completes the bearing. The NK 73/25 code states Fw 73 and width 25 mm directly; because the family has no inner ring, the 73 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: 5,600 r/min thermal reference and 6,300 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 73 mm seat. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 90 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 73 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 52.8/106 kN ratings and 300 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 73/25?",
        "a": "A NK 73/25 measures 73 mm bore/Fw × 90 mm outside diameter × 25 mm width (2.874 × 3.543 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 52.8 kN, static C0 106 kN, fatigue limit Pu 13.2 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 300 g."
      },
      {
        "q": "How is the NK 73/25 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 73 mm and width 25 mm, OD 90 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 73/25 run on an unhardened shaft?",
        "a": "No. In this execution the 73 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 73/25 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 73 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK73-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 73×90×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK73-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK73",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK73-25",
      "NK 73/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK73-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 73/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 73,
    "D_mm": 90,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 73.7,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 20.4,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 73/35 designates a flanged, machined outer ring filled with needle rollers and a cage for a 73 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 73 mm under-roller diameter and the 35 mm width, with the 90 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Speed planning separates the two ceilings: 5,600 r/min thermal reference and 6,300 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 73 mm seat. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 73 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 73/35 shares its 73×90×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 73.7/163 kN ratings and 430 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 73/35 need a hardened and ground shaft?",
        "a": "No. In this execution the 73 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 73/35?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 73 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 73/35 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 73/35 have?",
        "a": "A NK 73/35 measures 73 mm bore/Fw × 90 mm outside diameter × 35 mm width (2.874 × 3.543 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 73.7 kN, static C0 163 kN, fatigue limit Pu 20.4 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 430 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK73-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK73-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 73×90×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK73",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK73-35",
      "NK 73/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK75-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 75/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 92,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 53.9,
    "static_load_kN": 110,
    "fatigue_load_limit_kN": 13.7,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 320,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 75/25 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 75 mm bore seat and 92 mm OD. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 75 mm under-roller diameter and the 25 mm width, with the 92 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Selection arithmetic: C 53.9 kN against C0 110 kN gives a C0/C ratio of 2.04, and the 13.7 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 92 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 5,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 75 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 53.9/110 kN ratings and 320 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NK 75/25 have?",
        "a": "A NK 75/25 measures 75 mm bore/Fw × 92 mm outside diameter × 25 mm width (2.953 × 3.622 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 53.9 kN, static C0 110 kN, fatigue limit Pu 13.7 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 320 g."
      },
      {
        "q": "What does NK 75/25 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 75 mm and width 25 mm, OD 92 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 75/25 need a hardened and ground shaft?",
        "a": "No. In this execution the 75 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 75/25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 75 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK75-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×92×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK75-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK75",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK75-25",
      "NK 75/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK75-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 75/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 92,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 74.8,
    "static_load_kN": 170,
    "fatigue_load_limit_kN": 21.2,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 75/35: 75 mm Fw, 92 mm outside diameter, 35 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 75 mm Fw and 35 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Selection arithmetic: C 74.8 kN against C0 170 kN gives a C0/C ratio of 2.27, and the 21.2 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 75 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 74.8/170 kN ratings are SKF catalogue values for this exact execution (NK 75/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 74.8/170 kN ratings and 450 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 75/35 run on an unhardened shaft?",
        "a": "No. In this execution the 75 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 75/35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 75 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 75/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 75 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 75/35?",
        "a": "A NK 75/35 measures 75 mm bore/Fw × 92 mm outside diameter × 35 mm width (2.953 × 3.622 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 74.8 kN, static C0 170 kN, fatigue limit Pu 21.2 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 450 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK75-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK75-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×92×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK75",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK75-35",
      "NK 75/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKS75",
    "brand": "SKF",
    "manufacturer_designation": "NKS 75",
    "series": "NKS-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 95,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 70.4,
    "static_load_kN": 132,
    "fatigue_load_limit_kN": 16.6,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKS 75 is a ribbed machined-ring needle roller bearing (no inner ring) sized 75×95×28 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 75 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 75 mm Fw and 28 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NKS 75 shares its 75×95×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 70.4/132 kN ratings and 400 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKS 75 run on an unhardened shaft?",
        "a": "No. In this execution the 75 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NKS 75 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 75 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKS 75?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 75 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKS 75?",
        "a": "A NKS 75 measures 75 mm bore/Fw × 95 mm outside diameter × 28 mm width (2.953 × 3.74 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 70.4 kN, static C0 132 kN, fatigue limit Pu 16.6 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 400 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKS75-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×95×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS75",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKS75",
      "NKS 75"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK80-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 80/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 95,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 56.1,
    "static_load_kN": 127,
    "fatigue_load_limit_kN": 15.6,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 80/25 is a ribbed machined-ring needle roller bearing (no inner ring) sized 80×95×25 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 80 mm shaft journal completes the bearing. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 80 mm under-roller diameter and the 25 mm width, with the 95 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Speed planning separates the two ceilings: 5,000 r/min thermal reference and 5,600 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 80 mm seat. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NK 80/25 shares its 80×95×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 56.1/127 kN ratings and 300 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 80/25 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 80 mm and width 25 mm, OD 95 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 80/25 need a hardened and ground shaft?",
        "a": "No. In this execution the 80 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 80/25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 80 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 80/25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK80-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×95×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK80-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK80",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK80-25",
      "NK 80/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK80-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 80/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 95,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 24,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 80/35 designates a flanged, machined outer ring filled with needle rollers and a cage for a 80 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 80 mm Fw and 35 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Speed planning separates the two ceilings: 5,000 r/min thermal reference and 5,600 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 80 mm seat. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NK 80/35 shares its 80×95×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 76.5/190 kN ratings and 430 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NK 80/35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 80 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 80/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 80 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 80/35?",
        "a": "A NK 80/35 measures 80 mm bore/Fw × 95 mm outside diameter × 35 mm width (3.15 × 3.74 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 76.5 kN, static C0 190 kN, fatigue limit Pu 24 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 430 g."
      },
      {
        "q": "How is the NK 80/35 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 80 mm and width 35 mm, OD 95 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK80-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK80-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×95×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK80",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK80-35",
      "NK 80/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4914",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4914",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 100,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 84.2,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 20.8,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 49 needle roller bearings without inner ring include RNA 4914: 80 mm Fw, 100 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 80 mm under-roller diameter and the 30 mm width, with the 100 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 460 g at 80×100×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4914 shares its 80×100×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 84.2/163 kN ratings and 460 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RNA 4914 need a hardened and ground shaft?",
        "a": "No. In this execution the 80 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4914?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 80 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4914 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4914 have?",
        "a": "A RNA 4914 measures 80 mm bore/Fw × 100 mm outside diameter × 30 mm width (3.15 × 3.937 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 84.2 kN, static C0 163 kN, fatigue limit Pu 20.8 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 460 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4914-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×100×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4914",
      "RNA 4914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6914",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6914",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 100,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 128,
    "static_load_kN": 285,
    "fatigue_load_limit_kN": 36,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 860,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6914 is a ribbed machined-ring needle roller bearing (no inner ring) sized 80×100×54 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 80 mm shaft journal completes the bearing. The letters identify a flanged machined outer ring without inner ring; the figures give 80 mm Fw and 54 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 128/285 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 80 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 128/285 kN ratings are SKF catalogue values for this exact execution (RNA 6914); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 128/285 kN ratings and 860 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 6914 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 80 mm and width 54 mm, OD 100 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 6914 run on an unhardened shaft?",
        "a": "No. In this execution the 80 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 6914 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 80 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 6914?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 80 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6914-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×100×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6914",
      "RNA 6914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK85-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 85/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 105,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 69.3,
    "static_load_kN": 132,
    "fatigue_load_limit_kN": 16.6,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 85/25 designates a flanged, machined outer ring filled with needle rollers and a cage for a 85 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The NK 85/25 code states Fw 85 and width 25 mm directly; because the family has no inner ring, the 85 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 69.3/132 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 105 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NK 85/25 shares its 85×105×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 69.3/132 kN ratings and 430 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NK 85/25?",
        "a": "A NK 85/25 measures 85 mm bore/Fw × 105 mm outside diameter × 25 mm width (3.346 × 4.134 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 69.3 kN, static C0 132 kN, fatigue limit Pu 16.6 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 430 g."
      },
      {
        "q": "How is the NK 85/25 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 85 mm and width 25 mm, OD 105 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 85/25 run on an unhardened shaft?",
        "a": "No. In this execution the 85 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 85/25 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 85 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK85-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×105×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK85-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK85",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK85-25",
      "NK 85/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4915",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4915",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 105,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 84.2,
    "static_load_kN": 170,
    "fatigue_load_limit_kN": 21.6,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 490,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4915 designates a flanged, machined outer ring filled with needle rollers and a cage for a 85 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 85 mm Fw and 30 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 490 g at 85×105×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 84.2/170 kN ratings and 490 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 4915 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 85 mm and width 30 mm, OD 105 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4915 run on an unhardened shaft?",
        "a": "No. In this execution the 85 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4915 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 85 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4915?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 85 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4915-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×105×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4915",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4915",
      "RNA 4915"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK85-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 85/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 105,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 96.8,
    "static_load_kN": 200,
    "fatigue_load_limit_kN": 26,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 85/35 is a ribbed machined-ring needle roller bearing (no inner ring) sized 85×105×35 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 85 mm shaft journal completes the bearing. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 85 mm under-roller diameter and the 35 mm width, with the 105 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. For life calculation, the 96.8/200 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 85 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 96.8/200 kN ratings and 600 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 85/35 need a hardened and ground shaft?",
        "a": "No. In this execution the 85 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 85/35?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 85 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 85/35 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 85/35 have?",
        "a": "A NK 85/35 measures 85 mm bore/Fw × 105 mm outside diameter × 35 mm width (3.346 × 4.134 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 96.8 kN, static C0 200 kN, fatigue limit Pu 26 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 600 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK85-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK85-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×105×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK85",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK85-35",
      "NK 85/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6915",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6915",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 105,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 130,
    "static_load_kN": 290,
    "fatigue_load_limit_kN": 37.5,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 940,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6915 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 85 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: RNA gives the series and the numbers the boundary plan — 85 mm Fw for the shaft seat, 54 mm width; the 105 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 130/290 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 85 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 130/290 kN ratings and 940 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 6915 have?",
        "a": "A RNA 6915 measures 85 mm bore/Fw × 105 mm outside diameter × 54 mm width (3.346 × 4.134 × 2.126 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 130 kN, static C0 290 kN, fatigue limit Pu 37.5 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 940 g."
      },
      {
        "q": "What does RNA 6915 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 85 mm and width 54 mm, OD 105 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 6915 need a hardened and ground shaft?",
        "a": "No. In this execution the 85 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 6915?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 85 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6915-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×105×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6915",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6915",
      "RNA 6915"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK90-25",
    "brand": "SKF",
    "manufacturer_designation": "NK 90/25",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 110,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 72.1,
    "static_load_kN": 140,
    "fatigue_load_limit_kN": 18,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 90/25 belongs to the machined-ring needle roller family: an outer ring turned and ground to 110 mm with two retaining flanges, a roller-and-cage set inside, and envelope 90×110×25 mm on a hardened 90 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 90 mm under-roller diameter and the 25 mm width, with the 110 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 110 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 72.1/140 kN ratings are SKF catalogue values for this exact execution (NK 90/25); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 72.1/140 kN ratings and 450 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 90/25 need a hardened and ground shaft?",
        "a": "No. In this execution the 90 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 90/25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 90 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 90/25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 90/25 have?",
        "a": "A NK 90/25 measures 90 mm bore/Fw × 110 mm outside diameter × 25 mm width (3.543 × 4.331 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 72.1 kN, static C0 140 kN, fatigue limit Pu 18 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 450 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK90-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×110×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK90-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK90",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK90-25",
      "NK 90/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4916",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4916",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 110,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 88,
    "static_load_kN": 183,
    "fatigue_load_limit_kN": 23.2,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4916 belongs to the machined-ring needle roller family: an outer ring turned and ground to 110 mm with two retaining flanges, a roller-and-cage set inside, and envelope 90×110×30 mm on a hardened 90 mm shaft. Reading the designation: RNA gives the series and the numbers the boundary plan — 90 mm Fw for the shaft seat, 30 mm width; the 110 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 520 g at 90×110×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 88/183 kN ratings are SKF catalogue values for this exact execution (RNA 4916); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 88/183 kN ratings and 520 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 4916 have?",
        "a": "A RNA 4916 measures 90 mm bore/Fw × 110 mm outside diameter × 30 mm width (3.543 × 4.331 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 88 kN, static C0 183 kN, fatigue limit Pu 23.2 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 520 g."
      },
      {
        "q": "What does RNA 4916 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 90 mm and width 30 mm, OD 110 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4916 need a hardened and ground shaft?",
        "a": "No. In this execution the 90 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4916?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 90 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4916-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×110×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4916",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4916",
      "RNA 4916"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK90-35",
    "brand": "SKF",
    "manufacturer_designation": "NK 90/35",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 110,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 101,
    "static_load_kN": 216,
    "fatigue_load_limit_kN": 28,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 90/35 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 90 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 90 mm Fw and 35 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 101/216 kN ratings and 630 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NK 90/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 90 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 90/35?",
        "a": "A NK 90/35 measures 90 mm bore/Fw × 110 mm outside diameter × 35 mm width (3.543 × 4.331 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 101 kN, static C0 216 kN, fatigue limit Pu 28 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 630 g."
      },
      {
        "q": "How is the NK 90/35 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 90 mm and width 35 mm, OD 110 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 90/35 run on an unhardened shaft?",
        "a": "No. In this execution the 90 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK90-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK90-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×110×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK90",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK90-35",
      "NK 90/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6916",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6916",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 110,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 134,
    "static_load_kN": 315,
    "fatigue_load_limit_kN": 40,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 69 needle roller bearings without inner ring include RNA 6916: 90 mm Fw, 110 mm outside diameter, 54 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. The RNA 6916 code states Fw 90 and width 54 mm directly; because the family has no inner ring, the 90 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 134/315 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 6916 shares its 90×110×54 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 4,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 134/315 kN ratings and 990 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 6916?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 90 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 6916?",
        "a": "A RNA 6916 measures 90 mm bore/Fw × 110 mm outside diameter × 54 mm width (3.543 × 4.331 × 2.126 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 134 kN, static C0 315 kN, fatigue limit Pu 40 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 990 g."
      },
      {
        "q": "How is the RNA 6916 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 90 mm and width 54 mm, OD 110 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 6916 run on an unhardened shaft?",
        "a": "No. In this execution the 90 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6916-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×110×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6916",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6916",
      "RNA 6916"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK95-26",
    "brand": "SKF",
    "manufacturer_designation": "NK 95/26",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 95,
    "D_mm": 115,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 73.7,
    "static_load_kN": 146,
    "fatigue_load_limit_kN": 18.6,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 490,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF's machined-ring needle roller bearings without inner ring include NK 95/26: 95 mm Fw, 115 mm outside diameter, 26 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 95 mm under-roller diameter and the 26 mm width, with the 115 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Selection arithmetic: C 73.7 kN against C0 146 kN gives a C0/C ratio of 1.98, and the 18.6 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 95 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 73.7/146 kN ratings are SKF catalogue values for this exact execution (NK 95/26); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 73.7/146 kN ratings and 490 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NK 95/26 have?",
        "a": "A NK 95/26 measures 95 mm bore/Fw × 115 mm outside diameter × 26 mm width (3.74 × 4.528 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 73.7 kN, static C0 146 kN, fatigue limit Pu 18.6 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 490 g."
      },
      {
        "q": "What does NK 95/26 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 95 mm and width 26 mm, OD 115 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 95/26 need a hardened and ground shaft?",
        "a": "No. In this execution the 95 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 95/26?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 95 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK95-26-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 95×115×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK95-36-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK95",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK95-26",
      "NK 95/26"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK95-36",
    "brand": "SKF",
    "manufacturer_designation": "NK 95/36",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 95,
    "D_mm": 115,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 105,
    "static_load_kN": 232,
    "fatigue_load_limit_kN": 30,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 680,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers NK 95/36 in the machined-ring needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 95 mm bore seat and 115 mm OD. The letters identify a flanged machined outer ring without inner ring; the figures give 95 mm Fw and 36 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. Execution notes: the outer ring flanges are rolled from the ring material (no loose ribs to dislodge), the roller set is caged for low friction, and the TN option swaps in a polymer cage for quieter running. Selection arithmetic: C 105 kN against C0 232 kN gives a C0/C ratio of 2.21, and the 30 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 115 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 95 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 105/232 kN ratings and 680 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 95/36 run on an unhardened shaft?",
        "a": "No. In this execution the 95 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 95/36 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 95 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 95/36?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 95 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 95/36?",
        "a": "A NK 95/36 measures 95 mm bore/Fw × 115 mm outside diameter × 36 mm width (3.74 × 4.528 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 105 kN, static C0 232 kN, fatigue limit Pu 30 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 680 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK95-26-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK95-36-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 95×115×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK95",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK95-36",
      "NK 95/36"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK100-26",
    "brand": "SKF",
    "manufacturer_designation": "NK 100/26",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 120,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 156,
    "fatigue_load_limit_kN": 19.6,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 100/26 designates a flanged, machined outer ring filled with needle rollers and a cage for a 100 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 100 mm Fw and 26 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. The 520 g catalogue mass and 10.0 mm radial section ((120−100)/2) frame a rating of about 0.77 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 120 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 100 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 76.5/156 kN ratings are SKF catalogue values for this exact execution (NK 100/26); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 76.5/156 kN ratings and 520 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NK 100/26 run on an unhardened shaft?",
        "a": "No. In this execution the 100 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the NK 100/26 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 100 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 100/26?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 100 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 100/26?",
        "a": "A NK 100/26 measures 100 mm bore/Fw × 120 mm outside diameter × 26 mm width (3.937 × 4.724 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 76.5 kN, static C0 156 kN, fatigue limit Pu 19.6 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 520 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK100-26-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×120×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK100-36-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK100",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK100-26",
      "NK 100/26"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4917",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4917",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 120,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 108,
    "static_load_kN": 250,
    "fatigue_load_limit_kN": 31,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 660,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 4917 in the dimension series 49 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 100 mm bore seat and 120 mm OD. The RNA 4917 code states Fw 100 and width 35 mm directly; because the family has no inner ring, the 100 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 660 g at 100×120×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 100 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 108/250 kN ratings are SKF catalogue values for this exact execution (RNA 4917); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 108/250 kN ratings and 660 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 4917?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 100 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4917?",
        "a": "A RNA 4917 measures 100 mm bore/Fw × 120 mm outside diameter × 35 mm width (3.937 × 4.724 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 108 kN, static C0 250 kN, fatigue limit Pu 31 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 660 g."
      },
      {
        "q": "How is the RNA 4917 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 100 mm and width 35 mm, OD 120 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4917 run on an unhardened shaft?",
        "a": "No. In this execution the 100 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4917-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×120×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4917",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4917",
      "RNA 4917"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK100-36",
    "brand": "SKF",
    "manufacturer_designation": "NK 100/36",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 120,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 108,
    "static_load_kN": 250,
    "fatigue_load_limit_kN": 31,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 100/36 is a ribbed machined-ring needle roller bearing (no inner ring) sized 100×120×36 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 100 mm shaft journal completes the bearing. Reading the designation: NK gives the series and the numbers the boundary plan — 100 mm Fw for the shaft seat, 36 mm width; the 120 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. The 720 g catalogue mass and 10.0 mm radial section ((120−100)/2) frame a rating of about 1.08 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "piston-pin style pivots in hydraulic pumps",
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 108/250 kN ratings are SKF catalogue values for this exact execution (NK 100/36); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 108/250 kN ratings and 720 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NK 100/36 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 100/36 have?",
        "a": "A NK 100/36 measures 100 mm bore/Fw × 120 mm outside diameter × 36 mm width (3.937 × 4.724 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 108 kN, static C0 250 kN, fatigue limit Pu 31 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 720 g."
      },
      {
        "q": "What does NK 100/36 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 100 mm and width 36 mm, OD 120 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 100/36 need a hardened and ground shaft?",
        "a": "No. In this execution the 100 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK100-26-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK100-36-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×120×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK100",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK100-36",
      "NK 100/36"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6917",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6917",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 120,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 165,
    "static_load_kN": 425,
    "fatigue_load_limit_kN": 53,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 1200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 6917 designates a flanged, machined outer ring filled with needle rollers and a cage for a 100 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 100 mm under-roller diameter and the 63 mm width, with the 120 mm outside diameter set by the dimension series 69 needle roller bearings without inner ring plan. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 165/425 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 6917 shares its 100×120×63 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 165/425 kN ratings and 1200 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 6917?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 100 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 6917 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 6917 have?",
        "a": "A RNA 6917 measures 100 mm bore/Fw × 120 mm outside diameter × 63 mm width (3.937 × 4.724 × 2.48 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 165 kN, static C0 425 kN, fatigue limit Pu 53 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 1200 g."
      },
      {
        "q": "What does RNA 6917 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 100 mm and width 63 mm, OD 120 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6917-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×120×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6917",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6917",
      "RNA 6917"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK105-26",
    "brand": "SKF",
    "manufacturer_designation": "NK 105/26",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 105,
    "D_mm": 125,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 78.1,
    "static_load_kN": 166,
    "fatigue_load_limit_kN": 20.4,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 540,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 105/26 is a ribbed machined-ring needle roller bearing (no inner ring) sized 105×125×26 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 105 mm shaft journal completes the bearing. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 105 mm under-roller diameter and the 26 mm width, with the 125 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 540 g at 105×125×26 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 105 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 78.1/166 kN ratings are SKF catalogue values for this exact execution (NK 105/26); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 78.1/166 kN ratings and 540 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NK 105/26 need a hardened and ground shaft?",
        "a": "No. In this execution the 105 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 105/26?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 105 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 105/26 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NK 105/26 have?",
        "a": "A NK 105/26 measures 105 mm bore/Fw × 125 mm outside diameter × 26 mm width (4.134 × 4.921 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 78.1 kN, static C0 166 kN, fatigue limit Pu 20.4 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 540 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK105-26-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 105×125×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK105-36-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK105",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK105-26",
      "NK 105/26"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4918",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4918",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 105,
    "D_mm": 125,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 112,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 32.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4918 is a ribbed machined-ring needle roller bearing (no inner ring) sized 105×125×35 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 105 mm shaft journal completes the bearing. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 105 mm under-roller diameter and the 35 mm width, with the 125 mm outside diameter set by the dimension series 49 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 750 g at 105×125×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 105 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 3,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 105 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 112/265 kN ratings and 750 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 4918?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 105 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4918 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4918 have?",
        "a": "A RNA 4918 measures 105 mm bore/Fw × 125 mm outside diameter × 35 mm width (4.134 × 4.921 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 112 kN, static C0 265 kN, fatigue limit Pu 32.5 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 750 g."
      },
      {
        "q": "What does RNA 4918 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 105 mm and width 35 mm, OD 125 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4918-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 105×125×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4918",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4918",
      "RNA 4918"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK105-36",
    "brand": "SKF",
    "manufacturer_designation": "NK 105/36",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 105,
    "D_mm": 125,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 112,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 32.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 710,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NK 105/36 designates a flanged, machined outer ring filled with needle rollers and a cage for a 105 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 105 mm Fw and 36 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 710 g at 105×125×36 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 105 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 112/265 kN ratings and 710 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NK 105/36?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 105 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 105/36?",
        "a": "A NK 105/36 measures 105 mm bore/Fw × 125 mm outside diameter × 36 mm width (4.134 × 4.921 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 112 kN, static C0 265 kN, fatigue limit Pu 32.5 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 710 g."
      },
      {
        "q": "How is the NK 105/36 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 105 mm and width 36 mm, OD 125 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the NK 105/36 run on an unhardened shaft?",
        "a": "No. In this execution the 105 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK105-26-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK105-36-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 105×125×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK105",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK105-36",
      "NK 105/36"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6918",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6918",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 105,
    "D_mm": 125,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 172,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 55,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 1350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 6918 belongs to the machined-ring needle roller family: an outer ring turned and ground to 125 mm with two retaining flanges, a roller-and-cage set inside, and envelope 105×125×63 mm on a hardened 105 mm shaft. The letters identify a flanged machined outer ring without inner ring; the figures give 105 mm Fw and 63 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 172/450 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 105 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 172/450 kN ratings and 1350 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 634); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 6918 run on an unhardened shaft?",
        "a": "No. In this execution the 105 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 6918 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 105 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 6918?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 105 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 6918?",
        "a": "A RNA 6918 measures 105 mm bore/Fw × 125 mm outside diameter × 63 mm width (4.134 × 4.921 × 2.48 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 172 kN, static C0 450 kN, fatigue limit Pu 55 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 1350 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6918-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 105×125×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6918",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6918",
      "RNA 6918"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK110-30",
    "brand": "SKF",
    "manufacturer_designation": "NK 110/30",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 110,
    "D_mm": 130,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 96.8,
    "static_load_kN": 220,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 110/30 belongs to the machined-ring needle roller family: an outer ring turned and ground to 130 mm with two retaining flanges, a roller-and-cage set inside, and envelope 110×130×30 mm on a hardened 110 mm shaft. In SKF nomenclature NK families drop the inner ring: the numbers after the letters give the 110 mm under-roller diameter and the 30 mm width, with the 130 mm outside diameter set by the machined-ring needle roller bearings without inner ring plan. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Catalogue mass 650 g at 110×130×30 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 130 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 110 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 110 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 96.8/220 kN ratings and 650 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NK 110/30 mean in SKF part numbering?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 110 mm and width 30 mm, OD 130 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the NK 110/30 need a hardened and ground shaft?",
        "a": "No. In this execution the 110 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a NK 110/30?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 110 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NK 110/30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK110-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 110×130×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK110-40-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK110",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK110-30",
      "NK 110/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4919",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4919",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 110,
    "D_mm": 130,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 114,
    "static_load_kN": 270,
    "fatigue_load_limit_kN": 33.5,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4919 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 110 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 110 mm Fw and 35 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 720 g at 110×130×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 110 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 4919 shares its 110×130×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 114/270 kN ratings and 720 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 4919 run on an unhardened shaft?",
        "a": "No. In this execution the 110 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4919 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 110 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4919?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 110 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4919?",
        "a": "A RNA 4919 measures 110 mm bore/Fw × 130 mm outside diameter × 35 mm width (4.331 × 5.118 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 114 kN, static C0 270 kN, fatigue limit Pu 33.5 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 720 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4919-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 110×130×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4919",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4919",
      "RNA 4919"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NK110-40",
    "brand": "SKF",
    "manufacturer_designation": "NK 110/40",
    "series": "NK-series",
    "type": "needle",
    "d_mm": 110,
    "D_mm": 130,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 123,
    "static_load_kN": 305,
    "fatigue_load_limit_kN": 37.5,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NK 110/40 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 110 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 110 mm Fw and 40 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The wide NKS/NKIS siblings share the Fw and OD but add width for higher ratings — check both when the radial space allows a wider seat. Catalogue mass 830 g at 110×130×40 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 110 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 110 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 123/305 kN ratings are SKF catalogue values for this exact execution (NK 110/40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 123/305 kN ratings and 830 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NK 110/40 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 110 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NK 110/40?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 110 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NK 110/40?",
        "a": "A NK 110/40 measures 110 mm bore/Fw × 130 mm outside diameter × 40 mm width (4.331 × 5.118 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 123 kN, static C0 305 kN, fatigue limit Pu 37.5 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 830 g."
      },
      {
        "q": "How is the NK 110/40 designation read?",
        "a": "NK names a machined-ring needle roller bearing without inner ring: the figures give Fw 110 mm and width 40 mm, OD 130 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NK110-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NK110-40-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 110×130×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NK110",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NK110-40",
      "NK 110/40"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA6919",
    "brand": "SKF",
    "manufacturer_designation": "RNA 6919",
    "series": "RNA-69-series",
    "type": "needle",
    "d_mm": 110,
    "D_mm": 130,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 172,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 56,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 1450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 6919 in the dimension series 69 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 110 mm bore seat and 130 mm OD. Reading the designation: RNA gives the series and the numbers the boundary plan — 110 mm Fw for the shaft seat, 63 mm width; the 130 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. SKF offers this family open as standard; a matching IR inner ring can be added separately when the shaft cannot be hardened, which converts the envelope into the NKI/NA equivalent. For life calculation, the 172/465 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "guide rollers running on hardened tracks",
      "swing arms and lever pivots with oscillating duty",
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 110 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 172/465 kN ratings are SKF catalogue values for this exact execution (RNA 6919); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 172/465 kN ratings and 1450 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 6919 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 110 mm and width 63 mm, OD 130 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 6919 need a hardened and ground shaft?",
        "a": "No. In this execution the 110 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 6919?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 110 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 6919 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA6919-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 110×130×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA6919",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA6919",
      "RNA 6919"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4920",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4920",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 115,
    "D_mm": 140,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 125,
    "static_load_kN": 280,
    "fatigue_load_limit_kN": 34,
    "max_rpm": 4000,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 4000,
    "weight_g": 1150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4920 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 115 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 115 mm Fw and 40 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 1150 g at 115×140×40 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 140 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 115 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 125/280 kN ratings and 1150 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RNA 4920 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 115 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4920?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 115 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4920?",
        "a": "A RNA 4920 measures 115 mm bore/Fw × 140 mm outside diameter × 40 mm width (4.528 × 5.512 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 125 kN, static C0 280 kN, fatigue limit Pu 34 kN, limiting speed 4,000 r/min, reference speed 3,400 r/min, mass about 1150 g."
      },
      {
        "q": "How is the RNA 4920 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 115 mm and width 40 mm, OD 140 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4920-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 115×140×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4920",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4920",
      "RNA 4920"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4822",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4822",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 120,
    "D_mm": 140,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 93.5,
    "static_load_kN": 232,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 3800,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3800,
    "weight_g": 660,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4822 is a ribbed machined-ring needle roller bearing (no inner ring) sized 120×140×30 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 120 mm shaft journal completes the bearing. Reading the designation: RNA gives the series and the numbers the boundary plan — 120 mm Fw for the shaft seat, 30 mm width; the 140 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 660 g at 120×140×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 120 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 93.5/232 kN ratings are SKF catalogue values for this exact execution (RNA 4822); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 93.5/232 kN ratings and 660 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 4822 have?",
        "a": "A RNA 4822 measures 120 mm bore/Fw × 140 mm outside diameter × 30 mm width (4.724 × 5.512 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 93.5 kN, static C0 232 kN, fatigue limit Pu 27 kN, limiting speed 3,800 r/min, reference speed 3,400 r/min, mass about 660 g."
      },
      {
        "q": "What does RNA 4822 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 120 mm and width 30 mm, OD 140 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4822 need a hardened and ground shaft?",
        "a": "No. In this execution the 120 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4822?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 120 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4822-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 120×140×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4822",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4822",
      "RNA 4822"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4922",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4922",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 125,
    "D_mm": 150,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 130,
    "static_load_kN": 300,
    "fatigue_load_limit_kN": 35.5,
    "max_rpm": 3600,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3600,
    "weight_g": 1250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4922 designates a flanged, machined outer ring filled with needle rollers and a cage for a 125 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The RNA 4922 code states Fw 125 and width 40 mm directly; because the family has no inner ring, the 125 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 1250 g at 125×150×40 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 150 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 125 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 125 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 130/300 kN ratings are SKF catalogue values for this exact execution (RNA 4922); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 130/300 kN ratings and 1250 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 4922 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 125 mm and width 40 mm, OD 150 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4922 run on an unhardened shaft?",
        "a": "No. In this execution the 125 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4922 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 125 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4922?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 125 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4922-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 125×150×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4922",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4922",
      "RNA 4922"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4824",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4824",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 130,
    "D_mm": 150,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 99,
    "static_load_kN": 255,
    "fatigue_load_limit_kN": 29,
    "max_rpm": 3600,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3600,
    "weight_g": 730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 48 needle roller bearings without inner ring include RNA 4824: 130 mm Fw, 150 mm outside diameter, 30 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 130 mm under-roller diameter and the 30 mm width, with the 150 mm outside diameter set by the dimension series 48 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 730 g at 130×150×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 130 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 3,200 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 130 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 99/255 kN ratings and 730 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 4824?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 130 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4824 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4824 have?",
        "a": "A RNA 4824 measures 130 mm bore/Fw × 150 mm outside diameter × 30 mm width (5.118 × 5.906 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 99 kN, static C0 255 kN, fatigue limit Pu 29 kN, limiting speed 3,600 r/min, reference speed 3,200 r/min, mass about 730 g."
      },
      {
        "q": "What does RNA 4824 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 130 mm and width 30 mm, OD 150 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4824-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 130×150×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4824",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4824",
      "RNA 4824"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4924",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4924",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 135,
    "D_mm": 165,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 176,
    "static_load_kN": 405,
    "fatigue_load_limit_kN": 49,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 1850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 4924 in the dimension series 49 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 135 mm bore seat and 165 mm OD. The letters identify a flanged machined outer ring without inner ring; the figures give 135 mm Fw and 45 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 1850 g at 135×165×45 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 165 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 135 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 4924 shares its 135×165×45 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 3,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 176/405 kN ratings and 1850 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 4924?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 135 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4924?",
        "a": "A RNA 4924 measures 135 mm bore/Fw × 165 mm outside diameter × 45 mm width (5.315 × 6.496 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 176 kN, static C0 405 kN, fatigue limit Pu 49 kN, limiting speed 3,400 r/min, reference speed 3,000 r/min, mass about 1850 g."
      },
      {
        "q": "How is the RNA 4924 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 135 mm and width 45 mm, OD 165 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4924 run on an unhardened shaft?",
        "a": "No. In this execution the 135 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4924-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 135×165×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4924",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4924",
      "RNA 4924"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4826",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4826",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 145,
    "D_mm": 165,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 119,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 36.5,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4826 belongs to the machined-ring needle roller family: an outer ring turned and ground to 165 mm with two retaining flanges, a roller-and-cage set inside, and envelope 145×165×35 mm on a hardened 145 mm shaft. Reading the designation: RNA gives the series and the numbers the boundary plan — 145 mm Fw for the shaft seat, 35 mm width; the 165 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 990 g at 145×165×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 145 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4826 shares its 145×165×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 119/325 kN ratings and 990 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 4826 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 145 mm and width 35 mm, OD 165 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4826 need a hardened and ground shaft?",
        "a": "No. In this execution the 145 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4826?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 145 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4826 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4826-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 145×165×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4826",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4826",
      "RNA 4826"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4926",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4926",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 150,
    "D_mm": 180,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 198,
    "static_load_kN": 480,
    "fatigue_load_limit_kN": 57,
    "max_rpm": 3000,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3000,
    "weight_g": 2200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4926 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 150 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The RNA 4926 code states Fw 150 and width 50 mm directly; because the family has no inner ring, the 150 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 2200 g at 150×180×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 180 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 150 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 198/480 kN ratings and 2200 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 4926 run on an unhardened shaft?",
        "a": "No. In this execution the 150 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4926 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 150 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4926?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 150 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4926?",
        "a": "A RNA 4926 measures 150 mm bore/Fw × 180 mm outside diameter × 50 mm width (5.906 × 7.087 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 198 kN, static C0 480 kN, fatigue limit Pu 57 kN, limiting speed 3,000 r/min, reference speed 2,600 r/min, mass about 2200 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4926-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 150×180×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4926",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4926",
      "RNA 4926"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4828",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4828",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 155,
    "D_mm": 175,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 121,
    "static_load_kN": 345,
    "fatigue_load_limit_kN": 37.5,
    "max_rpm": 3000,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3000,
    "weight_g": 970,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4828 is a ribbed machined-ring needle roller bearing (no inner ring) sized 155×175×35 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 155 mm shaft journal completes the bearing. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 155 mm under-roller diameter and the 35 mm width, with the 175 mm outside diameter set by the dimension series 48 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 970 g at 155×175×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 155 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 121/345 kN ratings are SKF catalogue values for this exact execution (RNA 4828); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 121/345 kN ratings and 970 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the RNA 4828 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4828 have?",
        "a": "A RNA 4828 measures 155 mm bore/Fw × 175 mm outside diameter × 35 mm width (6.102 × 6.89 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 121 kN, static C0 345 kN, fatigue limit Pu 37.5 kN, limiting speed 3,000 r/min, reference speed 2,600 r/min, mass about 970 g."
      },
      {
        "q": "What does RNA 4828 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 155 mm and width 35 mm, OD 175 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4828 need a hardened and ground shaft?",
        "a": "No. In this execution the 155 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4828-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 155×175×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4828",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4828",
      "RNA 4828"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4928",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4928",
    "series": "RNA-49-series",
    "type": "needle",
    "d_mm": 160,
    "D_mm": 190,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 205,
    "static_load_kN": 510,
    "fatigue_load_limit_kN": 60,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 2350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4928 designates a flanged, machined outer ring filled with needle rollers and a cage for a 160 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 160 mm Fw and 50 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 2350 g at 160×190×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 190 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 160 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 160 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 205/510 kN ratings are SKF catalogue values for this exact execution (RNA 4928); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 205/510 kN ratings and 2350 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 4928?",
        "a": "A RNA 4928 measures 160 mm bore/Fw × 190 mm outside diameter × 50 mm width (6.299 × 7.48 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 205 kN, static C0 510 kN, fatigue limit Pu 60 kN, limiting speed 2,800 r/min, reference speed 2,400 r/min, mass about 2350 g."
      },
      {
        "q": "How is the RNA 4928 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 160 mm and width 50 mm, OD 190 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4928 run on an unhardened shaft?",
        "a": "No. In this execution the 160 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4928 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 160 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4928-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 160×190×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4928",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4928",
      "RNA 4928"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4830",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4830",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 165,
    "D_mm": 190,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 147,
    "static_load_kN": 415,
    "fatigue_load_limit_kN": 46.5,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 1600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4830 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 165 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 165 mm Fw and 40 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 1600 g at 165×190×40 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 165 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 4830 shares its 165×190×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 147/415 kN ratings and 1600 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a RNA 4830?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 165 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4830?",
        "a": "A RNA 4830 measures 165 mm bore/Fw × 190 mm outside diameter × 40 mm width (6.496 × 7.48 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 147 kN, static C0 415 kN, fatigue limit Pu 46.5 kN, limiting speed 2,800 r/min, reference speed 2,400 r/min, mass about 1600 g."
      },
      {
        "q": "How is the RNA 4830 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 165 mm and width 40 mm, OD 190 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4830 run on an unhardened shaft?",
        "a": "No. In this execution the 165 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4830-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 165×190×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4830",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4830",
      "RNA 4830"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4832",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4832",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 175,
    "D_mm": 200,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 157,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 49,
    "max_rpm": 2600,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2600,
    "weight_g": 1700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4832 designates a flanged, machined outer ring filled with needle rollers and a cage for a 175 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The RNA 4832 code states Fw 175 and width 40 mm directly; because the family has no inner ring, the 175 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 1700 g at 175×200×40 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 175 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 157/450 kN ratings and 1700 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 4832 run on an unhardened shaft?",
        "a": "No. In this execution the 175 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4832 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 175 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4832?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 175 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4832?",
        "a": "A RNA 4832 measures 175 mm bore/Fw × 200 mm outside diameter × 40 mm width (6.89 × 7.874 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 157 kN, static C0 450 kN, fatigue limit Pu 49 kN, limiting speed 2,600 r/min, reference speed 2,200 r/min, mass about 1700 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4832-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 175×200×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4832",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4832",
      "RNA 4832"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4834",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4834",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 185,
    "D_mm": 215,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 179,
    "static_load_kN": 520,
    "fatigue_load_limit_kN": 56,
    "max_rpm": 2400,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2400,
    "weight_g": 2550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "Where the shaft can be hardened and ground, SKF offers RNA 4834 in the dimension series 48 needle roller bearings without inner ring: outer ring only, needle rollers caged between integral flanges, 185 mm bore seat and 215 mm OD. The letters identify a flanged machined outer ring without inner ring; the figures give 185 mm Fw and 45 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 2550 g at 185×215×45 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 185 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 185 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 179/520 kN ratings are SKF catalogue values for this exact execution (RNA 4834); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 179/520 kN ratings and 2550 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the RNA 4834?",
        "a": "A RNA 4834 measures 185 mm bore/Fw × 215 mm outside diameter × 45 mm width (7.283 × 8.465 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 179 kN, static C0 520 kN, fatigue limit Pu 56 kN, limiting speed 2,400 r/min, reference speed 2,200 r/min, mass about 2550 g."
      },
      {
        "q": "How is the RNA 4834 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 185 mm and width 45 mm, OD 215 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4834 run on an unhardened shaft?",
        "a": "No. In this execution the 185 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4834 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 185 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4834-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 185×215×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4834",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4834",
      "RNA 4834"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4836",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4836",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 195,
    "D_mm": 225,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 190,
    "static_load_kN": 570,
    "fatigue_load_limit_kN": 60,
    "max_rpm": 2400,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2400,
    "weight_g": 2700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4836 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 195 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The RNA 4836 code states Fw 195 and width 45 mm directly; because the family has no inner ring, the 195 mm journal must be ground, hardened to 58–64 HRC and finished to the raceway tolerance the catalogue specifies. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 2700 g at 195×225×45 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 195 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 4836 shares its 195×225×45 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 2,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 190/570 kN ratings and 2700 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RNA 4836 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 195 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4836?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 195 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4836?",
        "a": "A RNA 4836 measures 195 mm bore/Fw × 225 mm outside diameter × 45 mm width (7.677 × 8.858 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 190 kN, static C0 570 kN, fatigue limit Pu 60 kN, limiting speed 2,400 r/min, reference speed 2,000 r/min, mass about 2700 g."
      },
      {
        "q": "How is the RNA 4836 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 195 mm and width 45 mm, OD 225 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4836-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 195×225×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4836",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4836",
      "RNA 4836"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4838",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4838",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 210,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 220,
    "static_load_kN": 710,
    "fatigue_load_limit_kN": 73.5,
    "max_rpm": 2200,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2200,
    "weight_g": 3200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4838 designates a flanged, machined outer ring filled with needle rollers and a cage for a 210 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 210 mm Fw and 50 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 3200 g at 210×240×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 210 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 220/710 kN ratings and 3200 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 4838 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 210 mm and width 50 mm, OD 240 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4838 run on an unhardened shaft?",
        "a": "No. In this execution the 210 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4838 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 210 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4838?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 210 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4838-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 210×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4838",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4838",
      "RNA 4838"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4840",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4840",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 220,
    "D_mm": 250,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 224,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 75,
    "max_rpm": 2000,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 2000,
    "weight_g": 3350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4840 belongs to the machined-ring needle roller family: an outer ring turned and ground to 250 mm with two retaining flanges, a roller-and-cage set inside, and envelope 220×250×50 mm on a hardened 220 mm shaft. Reading the designation: RNA gives the series and the numbers the boundary plan — 220 mm Fw for the shaft seat, 50 mm width; the 250 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 3350 g at 220×250×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 250 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 220 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 1,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 220 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 224/735 kN ratings and 3350 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RNA 4840 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 220 mm and width 50 mm, OD 250 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4840 need a hardened and ground shaft?",
        "a": "No. In this execution the 220 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4840?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 220 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4840 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4840-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 220×250×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4840",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4840",
      "RNA 4840"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4844",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4844",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 240,
    "D_mm": 270,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 238,
    "static_load_kN": 815,
    "fatigue_load_limit_kN": 81.5,
    "max_rpm": 1900,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 1900,
    "weight_g": 3600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF's dimension series 48 needle roller bearings without inner ring include RNA 4844: 240 mm Fw, 270 mm outside diameter, 50 mm width — a machined and ground outer ring whose rolled flanges retain the needle rollers, running on the shaft as the inner raceway. Reading the designation: RNA gives the series and the numbers the boundary plan — 240 mm Fw for the shaft seat, 50 mm width; the 270 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 3600 g at 240×270×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 270 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 240 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 238/815 kN ratings are SKF catalogue values for this exact execution (RNA 4844); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 238/815 kN ratings and 3600 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RNA 4844 need a hardened and ground shaft?",
        "a": "No. In this execution the 240 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4844?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 240 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4844 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4844 have?",
        "a": "A RNA 4844 measures 240 mm bore/Fw × 270 mm outside diameter × 50 mm width (9.449 × 10.63 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 238 kN, static C0 815 kN, fatigue limit Pu 81.5 kN, limiting speed 1,900 r/min, reference speed 1,700 r/min, mass about 3600 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4844-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 240×270×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4844",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4844",
      "RNA 4844"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4848",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4848",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 265,
    "D_mm": 300,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 347,
    "static_load_kN": 1120,
    "fatigue_load_limit_kN": 112,
    "max_rpm": 1700,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 1700,
    "weight_g": 5400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4848 is a ribbed machined-ring needle roller bearing (no inner ring) sized 265×300×60 mm: the ground outside diameter seats in the housing, the integral flanges hold the rollers, and the 265 mm shaft journal completes the bearing. Reading the designation: RNA gives the series and the numbers the boundary plan — 265 mm Fw for the shaft seat, 60 mm width; the 300 mm OD comes from the dimension series, and the absence of an inner ring is built into the family name. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 5400 g at 265×300×60 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Fit the outer ring with a press and a fitting sleeve, not by hammering the flanges — rolled flanges chip; the 300 mm ground OD takes the press fit that prevents outer-ring creep in oscillating duty.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 265 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RNA 4848 shares its 265×300×60 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 347/1120 kN ratings and 5400 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a RNA 4848?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 265 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RNA 4848 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RNA 4848 have?",
        "a": "A RNA 4848 measures 265 mm bore/Fw × 300 mm outside diameter × 60 mm width (10.433 × 11.811 × 2.362 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 347 kN, static C0 1120 kN, fatigue limit Pu 112 kN, limiting speed 1,700 r/min, reference speed 1,500 r/min, mass about 5400 g."
      },
      {
        "q": "What does RNA 4848 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 265 mm and width 60 mm, OD 300 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4848-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 265×300×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4848",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4848",
      "RNA 4848"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4852",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4852",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 285,
    "D_mm": 320,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 358,
    "static_load_kN": 1200,
    "fatigue_load_limit_kN": 118,
    "max_rpm": 1500,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 1500,
    "weight_g": 5800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RNA 4852 designates a flanged, machined outer ring filled with needle rollers and a cage for a 285 mm shaft — heavier section and higher accuracy than a drawn cup, with no inner ring so the journal is the raceway. The letters identify a flanged machined outer ring without inner ring; the figures give 285 mm Fw and 60 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 5800 g at 285×320×60 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 285 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: RNA 4852 shares its 285×320×60 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 1,400 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 358/1200 kN ratings and 5800 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RNA 4852 designation read?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 285 mm and width 60 mm, OD 320 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Can the RNA 4852 run on an unhardened shaft?",
        "a": "No. In this execution the 285 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4852 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 285 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4852?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 285 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 17.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4852-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 285×320×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4852",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4852",
      "RNA 4852"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4856",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4856",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 305,
    "D_mm": 350,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 429,
    "static_load_kN": 1320,
    "fatigue_load_limit_kN": 129,
    "max_rpm": 1400,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 1400,
    "weight_g": 9300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4856 is a machined-ring needle roller bearing without an inner ring: a solid outer ring with integral flanges guiding the caged rollers, riding directly on a 305 mm hardened shaft journal, as listed in SKF catalogue PUB BU/P1 17000. The letters identify a flanged machined outer ring without inner ring; the figures give 305 mm Fw and 69 mm B — dimensionally identical envelopes exist with an inner ring under the NA/NKI names, which changes the shaft seat entirely. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 9300 g at 305×350×69 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: the flanged outer ring presses into the H7 housing bore against its flange face; the shaft (hardened to 58–64 HRC, ground) enters afterwards, and axial retention is by the housing wall plus a cover washer.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "rapid raceway scoring when the shaft journal hardness drops below 58 HRC or the ground finish wears away"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 305 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 305 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 429/1320 kN ratings are SKF catalogue values for this exact execution (RNA 4856); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 429/1320 kN ratings and 9300 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RNA 4856 run on an unhardened shaft?",
        "a": "No. In this execution the 305 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "How should the RNA 4856 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 305 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RNA 4856?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 305 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 22.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RNA 4856?",
        "a": "A RNA 4856 measures 305 mm bore/Fw × 350 mm outside diameter × 69 mm width (12.008 × 13.78 × 2.717 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 429 kN, static C0 1320 kN, fatigue limit Pu 129 kN, limiting speed 1,400 r/min, reference speed 1,300 r/min, mass about 9300 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4856-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 305×350×69 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4856",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4856",
      "RNA 4856"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RNA4860",
    "brand": "SKF",
    "manufacturer_designation": "RNA 4860",
    "series": "RNA-48-series",
    "type": "needle",
    "d_mm": 330,
    "D_mm": 380,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 594,
    "static_load_kN": 1800,
    "fatigue_load_limit_kN": 173,
    "max_rpm": 1300,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1300,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "RNA 4860 belongs to the machined-ring needle roller family: an outer ring turned and ground to 380 mm with two retaining flanges, a roller-and-cage set inside, and envelope 330×380×80 mm on a hardened 330 mm shaft. In SKF nomenclature RNA families drop the inner ring: the numbers after the letters give the 330 mm under-roller diameter and the 80 mm width, with the 380 mm outside diameter set by the dimension series 48 needle roller bearings without inner ring plan. The machined ring is through-hardened and ground on OD, bore-side raceway and faces; the flanged lip design means the housing shoulder can be omitted — the ring clamps axially between housing wall and cover washer. Catalogue mass 12500 g at 330×380×80 mm makes this one of the highest capacity-per-gram choices in the dimension series 48 needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Grease through the housing groove before fitting the shaft; the integral flanges hold the grease film at the roller ends, which is where these bearings first starve.",
    "applications": [
      "cam followers built up from separate components",
      "crank pins and eccentrics where the hardened journal is the raceway",
      "gearbox planetary and idler gears on hardened pins",
      "piston-pin style pivots in hydraulic pumps"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "smearing of rollers and journal during idle periods because the radial section holds too little lubricant"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 330 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 594/1800 kN ratings are SKF catalogue values for this exact execution (RNA 4860); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 594/1800 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 7.3 of PUB BU/P1 17000 (PDF table page 636); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RNA 4860 have?",
        "a": "A RNA 4860 measures 330 mm bore/Fw × 380 mm outside diameter × 80 mm width (12.992 × 14.961 × 3.15 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 594 kN, static C0 1800 kN, fatigue limit Pu 173 kN, limiting speed 1,300 r/min, reference speed 1,100 r/min, mass about 12500 g."
      },
      {
        "q": "What does RNA 4860 mean in SKF part numbering?",
        "a": "RNA names a machined-ring needle roller bearing without inner ring: the figures give Fw 330 mm and width 80 mm, OD 380 mm comes from the dimension series, and the flanged outer ring retains the caged rollers."
      },
      {
        "q": "Does the RNA 4860 need a hardened and ground shaft?",
        "a": "No. In this execution the 330 mm shaft journal is the inner raceway: it must be ground and hardened to 58–64 HRC (with matching housing bore quality on the outside). If the shaft cannot meet that, order the inner-ring sibling (NKI/NA execution) plus its ground inner ring instead."
      },
      {
        "q": "What mounting mistakes ruin a RNA 4860?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 330 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RNA4860-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 330×380×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "RNA4860",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.3 machined rings with flanges, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RNA4860",
      "RNA 4860"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI5-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 5/12 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 15,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 3.8,
    "static_load_kN": 4.25,
    "fatigue_load_limit_kN": 0.465,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 12,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 5/12 TN provides the full machined-ring needle roller construction: ground inner ring on a 5 mm seat, flanged outer ring at 15 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The designation NKI 5/12 TN tells you the envelope — 5×15×12 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Catalogue mass 12 g at 5×15×12 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the NKI 5/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 3.8/4.25 kN ratings and 12 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKI 5/12 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 5 mm bore, 12 mm width, 15 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 5/12 TN run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 5/12 TN carries its own hardened, ground inner ring on a 5 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 5/12 TN be mounted?",
        "a": "Mount the inner ring on the 5 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 5/12 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 5 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI5-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 5×15×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI5-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI5",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI5-12-TN",
      "NKI 5/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI5-16-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 5/16 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 5,
    "D_mm": 15,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.01,
    "static_load_kN": 5.85,
    "fatigue_load_limit_kN": 0.67,
    "max_rpm": 36000,
    "reference_speed_rpm": 32000,
    "limiting_speed_rpm": 36000,
    "weight_g": 15,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 5/16 TN measures 5×15×16 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The NKI 5/16 TN code gives bore 5 mm and width 16 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. The 15 g catalogue mass and 5.0 mm radial section ((15−5)/2) frame a rating of about 1.00 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: heat or press the inner ring onto the 5 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 16 mm assembly for free rotation before applying load.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At Fw 5 mm the rolling elements are under two millimetres long — handle the NKI 5/16 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 5.01/5.85 kN ratings and 15 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 5/16 TN?",
        "a": "A NKI 5/16 TN measures 5 mm bore/Fw × 15 mm outside diameter × 16 mm width (0.197 × 0.591 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.01 kN, static C0 5.85 kN, fatigue limit Pu 0.67 kN, limiting speed 36,000 r/min, reference speed 32,000 r/min, mass about 15 g."
      },
      {
        "q": "How is the NKI 5/16 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 5 mm bore, 16 mm width, 15 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 5/16 TN run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 5/16 TN carries its own hardened, ground inner ring on a 5 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 5/16 TN be mounted?",
        "a": "Mount the inner ring on the 5 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI5-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI5-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 5×15×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI5",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI5-16-TN",
      "NKI 5/16 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI6-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 6/12 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 16,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.4,
    "static_load_kN": 5.2,
    "fatigue_load_limit_kN": 0.57,
    "max_rpm": 34000,
    "reference_speed_rpm": 30000,
    "limiting_speed_rpm": 34000,
    "weight_g": 14,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 6/12 TN denotes a complete needle roller bearing for a 6 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 16 mm OD and 12 mm width. The designation NKI 6/12 TN tells you the envelope — 6×16×12 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 4.4 kN against C0 5.2 kN gives a C0/C ratio of 1.18, and the 0.57 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 6 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 12 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the NKI 6/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 4.4/5.2 kN ratings and 14 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKI 6/12 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 6 mm bore, 12 mm width, 16 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 6/12 TN run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 6/12 TN carries its own hardened, ground inner ring on a 6 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 6/12 TN be mounted?",
        "a": "Mount the inner ring on the 6 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 6/12 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 6 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI6-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 6×16×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI6-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI6",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI6-12-TN",
      "NKI 6/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI6-16-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 6/16 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 6,
    "D_mm": 16,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.72,
    "static_load_kN": 7.2,
    "fatigue_load_limit_kN": 0.815,
    "max_rpm": 34000,
    "reference_speed_rpm": 30000,
    "limiting_speed_rpm": 34000,
    "weight_g": 17,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 6/16 TN is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 6 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 6 mm d and 16 mm B, the 16 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. The 17 g catalogue mass and 5.0 mm radial section ((16−6)/2) frame a rating of about 0.95 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 16 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At Fw 6 mm the rolling elements are under two millimetres long — handle the NKI 6/16 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 5.72/7.2 kN ratings are SKF catalogue values for this exact execution (NKI 6/16 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 5.72/7.2 kN ratings and 17 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 6/16 TN have?",
        "a": "A NKI 6/16 TN measures 6 mm bore/Fw × 16 mm outside diameter × 16 mm width (0.236 × 0.63 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.72 kN, static C0 7.2 kN, fatigue limit Pu 0.815 kN, limiting speed 34,000 r/min, reference speed 30,000 r/min, mass about 17 g."
      },
      {
        "q": "What does NKI 6/16 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 6 mm bore, 16 mm width, 16 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 6/16 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 6/16 TN carries its own hardened, ground inner ring on a 6 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 6/16 TN?",
        "a": "Mount the inner ring on the 6 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI6-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI6-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 6×16×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI6",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI6-16-TN",
      "NKI 6/16 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI7-12-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 7/12 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 17,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 4.57,
    "static_load_kN": 5.7,
    "fatigue_load_limit_kN": 0.63,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 14,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 7/12 TN measures 7×17×12 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 7 mm bore (d), 12 mm width; the 17 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 4.57 kN against C0 5.7 kN gives a C0/C ratio of 1.25, and the 0.63 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 12 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the NKI 7/12 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 4.57/5.7 kN ratings are SKF catalogue values for this exact execution (NKI 7/12 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 4.57/5.7 kN ratings and 14 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKI 7/12 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 7 mm bore, 12 mm width, 17 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 7/12 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 7/12 TN carries its own hardened, ground inner ring on a 7 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 7/12 TN?",
        "a": "Mount the inner ring on the 7 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 7/12 TN sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI7-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 7×17×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI7-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI7",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI7-12-TN",
      "NKI 7/12 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI7-16-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 7/16 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 17,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.94,
    "static_load_kN": 8,
    "fatigue_load_limit_kN": 0.9,
    "max_rpm": 32000,
    "reference_speed_rpm": 28000,
    "limiting_speed_rpm": 32000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 7/16 TN in the machined-ring needle roller bearings with inner ring with boundary dimensions 7×17×16 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 7 mm d and 16 mm B, the 17 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. For life calculation, the 5.94/8 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 16 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the NKI 7/16 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 5.94/8 kN ratings are SKF catalogue values for this exact execution (NKI 7/16 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 5.94/8 kN ratings and 18 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 7/16 TN have?",
        "a": "A NKI 7/16 TN measures 7 mm bore/Fw × 17 mm outside diameter × 16 mm width (0.276 × 0.669 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.94 kN, static C0 8 kN, fatigue limit Pu 0.9 kN, limiting speed 32,000 r/min, reference speed 28,000 r/min, mass about 18 g."
      },
      {
        "q": "What does NKI 7/16 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 7 mm bore, 16 mm width, 17 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 7/16 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 7/16 TN carries its own hardened, ground inner ring on a 7 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 7/16 TN?",
        "a": "Mount the inner ring on the 7 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI7-12-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI7-16-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 7×17×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI7",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI7-16-TN",
      "NKI 7/16 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI9-12",
    "brand": "SKF",
    "manufacturer_designation": "NKI 9/12",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 19,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 6.71,
    "static_load_kN": 8.15,
    "fatigue_load_limit_kN": 0.965,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 17,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 9/12 provides the full machined-ring needle roller construction: ground inner ring on a 9 mm seat, flanged outer ring at 19 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The NKI 9/12 code gives bore 9 mm and width 12 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Selection arithmetic: C 6.71 kN against C0 8.15 kN gives a C0/C ratio of 1.21, and the 0.965 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 9 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 6.71/8.15 kN ratings are SKF catalogue values for this exact execution (NKI 9/12); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 6.71/8.15 kN ratings and 17 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKI 9/12 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 9 mm bore, 12 mm width, 19 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 9/12 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 9/12 carries its own hardened, ground inner ring on a 9 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 9/12 be mounted?",
        "a": "Mount the inner ring on the 9 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 9/12?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 9 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI9-12-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 9×19×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI9-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI9",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI9-12",
      "NKI 9/12"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI9-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 9/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 9,
    "D_mm": 19,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12,
    "fatigue_load_limit_kN": 1.43,
    "max_rpm": 30000,
    "reference_speed_rpm": 26000,
    "limiting_speed_rpm": 30000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 9/16 measures 9×19×16 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The NKI 9/16 code gives bore 9 mm and width 16 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Selection arithmetic: C 9.13 kN against C0 12 kN gives a C0/C ratio of 1.31, and the 1.43 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 9 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 9.13/12 kN ratings and 22 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKI 9/16 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 9/16 carries its own hardened, ground inner ring on a 9 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 9/16 be mounted?",
        "a": "Mount the inner ring on the 9 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 9/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 9 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 9/16?",
        "a": "A NKI 9/16 measures 9 mm bore/Fw × 19 mm outside diameter × 16 mm width (0.354 × 0.748 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12 kN, fatigue limit Pu 1.43 kN, limiting speed 30,000 r/min, reference speed 26,000 r/min, mass about 22 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI9-12-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI9-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NKI9",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI9-16",
      "NKI 9/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4900",
    "brand": "SKF",
    "manufacturer_designation": "NA 4900",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.8,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 1.22,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 24,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 10 mm shaft that cannot be hardened on site, NA 4900 adds a hardened, ground inner ring to the machined needle roller design: envelope 10×22×13 mm per the dimension series 49 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 10 mm bore (d), 13 mm width; the 22 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 24 g at 10×22×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4900 shares its 10×22×13 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 8.8/10.4 kN ratings and 24 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 4900 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 10 mm bore, 13 mm width, 22 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4900 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4900 carries its own hardened, ground inner ring on a 10 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4900?",
        "a": "Mount the inner ring on the 10 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4900 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4900-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4900",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4900",
      "NA 4900"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4900-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4900.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.37,
    "static_load_kN": 8.15,
    "fatigue_load_limit_kN": 0.965,
    "max_rpm": 12000,
    "limiting_speed_rpm": 12000,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 10 mm shaft that cannot be hardened on site, NA 4900.2RS adds a hardened, ground inner ring to the machined needle roller design: envelope 10×22×14 mm per the dimension series 49 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 10 mm d and 14 mm B, the 22 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. For life calculation, the 7.37/8.15 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 7.37/8.15 kN ratings are SKF catalogue values for this exact execution (NA 4900.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 7.37/8.15 kN ratings and 25 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4900.2RS sealed?",
        "a": "Yes — the 2RS execution seals both faces with rubber contact seals; note its wider outer ring (B and s differ from the open execution), so housing dimensions must be re-checked."
      },
      {
        "q": "Which dimensions does the NA 4900.2RS have?",
        "a": "A NA 4900.2RS measures 10 mm bore/Fw × 22 mm outside diameter × 14 mm width (0.394 × 0.866 × 0.551 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.37 kN, static C0 8.15 kN, fatigue limit Pu 0.965 kN, limiting speed 12,000 r/min, mass about 25 g."
      },
      {
        "q": "What does NA 4900.2RS mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 10 mm bore, 14 mm width, 22 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4900.2RS need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4900.2RS carries its own hardened, ground inner ring on a 10 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4900-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4900",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4900-2RS",
      "NA 4900.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI10-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 10/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 10.2,
    "static_load_kN": 12.5,
    "fatigue_load_limit_kN": 1.5,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 10/16 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 10 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 10 mm d and 16 mm B, the 22 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Selection arithmetic: C 10.2 kN against C0 12.5 kN gives a C0/C ratio of 1.23, and the 1.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 10/16 shares its 10×22×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 10.2/12.5 kN ratings and 29 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKI 10/16 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 10 mm bore, 16 mm width, 22 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 10/16 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 10/16 carries its own hardened, ground inner ring on a 10 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 10/16?",
        "a": "Mount the inner ring on the 10 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 10/16 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI10-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI10-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI10-16",
      "NKI 10/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI10-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 10/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 2,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 10/20 provides the full machined-ring needle roller construction: ground inner ring on a 10 mm seat, flanged outer ring at 22 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The NKI 10/20 code gives bore 10 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Selection arithmetic: C 12.8 kN against C0 16.6 kN gives a C0/C ratio of 1.30, and the 2 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 10 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 20 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 22 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKI 10/20 shares its 10×22×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 24,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 12.8/16.6 kN ratings and 37 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 10/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 10 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 10/20?",
        "a": "A NKI 10/20 measures 10 mm bore/Fw × 22 mm outside diameter × 20 mm width (0.394 × 0.866 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.8 kN, static C0 16.6 kN, fatigue limit Pu 2 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 37 g."
      },
      {
        "q": "How is the NKI 10/20 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 10 mm bore, 20 mm width, 22 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 10/20 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 10/20 carries its own hardened, ground inner ring on a 10 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI10-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI10-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI10",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI10-20",
      "NKI 10/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4901",
    "brand": "SKF",
    "manufacturer_designation": "NA 4901",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.9,
    "static_load_kN": 12.2,
    "fatigue_load_limit_kN": 1.46,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4901 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 12 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NA 4901 code gives bore 12 mm and width 13 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 26 g at 12×24×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 9.9/12.2 kN ratings and 26 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 4901?",
        "a": "A NA 4901 measures 12 mm bore/Fw × 24 mm outside diameter × 13 mm width (0.472 × 0.945 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.9 kN, static C0 12.2 kN, fatigue limit Pu 1.46 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 26 g."
      },
      {
        "q": "How is the NA 4901 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 12 mm bore, 13 mm width, 24 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4901 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4901 carries its own hardened, ground inner ring on a 12 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4901 be mounted?",
        "a": "Mount the inner ring on the 12 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4901-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4901",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4901",
      "NA 4901"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4901-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4901.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.09,
    "static_load_kN": 9.65,
    "fatigue_load_limit_kN": 1.14,
    "max_rpm": 11000,
    "limiting_speed_rpm": 11000,
    "weight_g": 28,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4901.2RS provides the full machined-ring needle roller construction: ground inner ring on a 12 mm seat, flanged outer ring at 24 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The NA 4901.2RS code gives bore 12 mm and width 14 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 11,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 12 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 14 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 8.09/9.65 kN ratings are SKF catalogue values for this exact execution (NA 4901.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 8.09/9.65 kN ratings and 28 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 4901.2RS?",
        "a": "A NA 4901.2RS measures 12 mm bore/Fw × 24 mm outside diameter × 14 mm width (0.472 × 0.945 × 0.551 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.09 kN, static C0 9.65 kN, fatigue limit Pu 1.14 kN, limiting speed 11,000 r/min, mass about 28 g."
      },
      {
        "q": "How is the NA 4901.2RS designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 12 mm bore, 14 mm width, 24 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4901.2RS run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4901.2RS carries its own hardened, ground inner ring on a 12 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4901.2RS be mounted?",
        "a": "Mount the inner ring on the 12 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4901-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4901",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4901-2RS",
      "NA 4901.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI12-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 12/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.7,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.8,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 12 mm shaft that cannot be hardened on site, NKI 12/16 adds a hardened, ground inner ring to the machined needle roller design: envelope 12×24×16 mm per the machined-ring needle roller bearings with inner ring plan. The designation NKI 12/16 tells you the envelope — 12×24×16 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 12 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 16 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 11.7/15.3 kN ratings are SKF catalogue values for this exact execution (NKI 12/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 11.7/15.3 kN ratings and 33 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 12/16?",
        "a": "A NKI 12/16 measures 12 mm bore/Fw × 24 mm outside diameter × 16 mm width (0.472 × 0.945 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.7 kN, static C0 15.3 kN, fatigue limit Pu 1.8 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 33 g."
      },
      {
        "q": "How is the NKI 12/16 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 12 mm bore, 16 mm width, 24 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 12/16 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 12/16 carries its own hardened, ground inner ring on a 12 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 12/16 be mounted?",
        "a": "Mount the inner ring on the 12 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI12-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI12-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKIA5901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×16 mm envelope, but catalogue C/C0 differ between the executions (11.7/15.3 vs 8.09/9.65 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI12-16",
      "NKI 12/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI12-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 12/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 20,
    "fatigue_load_limit_kN": 2.4,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 12/20 denotes a complete needle roller bearing for a 12 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 24 mm OD and 20 mm width. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 12 mm d and 20 mm B, the 24 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 14.5/20 kN ratings are SKF catalogue values for this exact execution (NKI 12/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 14.5/20 kN ratings and 42 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 12/20?",
        "a": "Mount the inner ring on the 12 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 12/20 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 12/20 have?",
        "a": "A NKI 12/20 measures 12 mm bore/Fw × 24 mm outside diameter × 20 mm width (0.472 × 0.945 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 14.5 kN, static C0 20 kN, fatigue limit Pu 2.4 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 42 g."
      },
      {
        "q": "What does NKI 12/20 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 12 mm bore, 20 mm width, 24 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI12-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI12-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI12",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI12-20",
      "NKI 12/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6901",
    "brand": "SKF",
    "manufacturer_designation": "NA 6901",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.1,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 2.75,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 46,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 12 mm shaft that cannot be hardened on site, NA 6901 adds a hardened, ground inner ring to the machined needle roller design: envelope 12×24×22 mm per the dimension series 69 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 12 mm d and 22 mm B, the 24 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 16.1/23.2 kN ratings and 46 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 6901 have?",
        "a": "A NA 6901 measures 12 mm bore/Fw × 24 mm outside diameter × 22 mm width (0.472 × 0.945 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.1 kN, static C0 23.2 kN, fatigue limit Pu 2.75 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 46 g."
      },
      {
        "q": "What does NA 6901 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 12 mm bore, 22 mm width, 24 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 6901 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6901 carries its own hardened, ground inner ring on a 12 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 6901?",
        "a": "Mount the inner ring on the 12 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6901-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6901",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6901",
      "NA 6901"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI15-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 15/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 27,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.4,
    "static_load_kN": 19,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 24000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 24000,
    "weight_g": 39,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 15/16 provides the full machined-ring needle roller construction: ground inner ring on a 15 mm seat, flanged outer ring at 27 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The NKI 15/16 code gives bore 15 mm and width 16 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. The 39 g catalogue mass and 6.0 mm radial section ((27−15)/2) frame a rating of about 0.89 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 16 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 27 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKI 15/16 shares its 15×27×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 20,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 13.4/19 kN ratings and 39 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 15/16?",
        "a": "A NKI 15/16 measures 15 mm bore/Fw × 27 mm outside diameter × 16 mm width (0.591 × 1.063 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.4 kN, static C0 19 kN, fatigue limit Pu 2.28 kN, limiting speed 24,000 r/min, reference speed 20,000 r/min, mass about 39 g."
      },
      {
        "q": "How is the NKI 15/16 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 15 mm bore, 16 mm width, 27 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 15/16 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 15/16 carries its own hardened, ground inner ring on a 15 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 15/16 be mounted?",
        "a": "Mount the inner ring on the 15 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI15-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NKI15-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI15-16",
      "NKI 15/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI15-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 15/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 27,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 24000,
    "reference_speed_rpm": 20000,
    "limiting_speed_rpm": 24000,
    "weight_g": 49,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 15/20 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 15 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 15 mm bore (d), 20 mm width; the 27 mm OD follows the dimension series, and the inner ring is a separate ground component. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. The 49 g catalogue mass and 6.0 mm radial section ((27−15)/2) frame a rating of about 1.10 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 27 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 20,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 16.5/25.5 kN ratings and 49 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 15/20?",
        "a": "Mount the inner ring on the 15 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 15/20 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 15/20 have?",
        "a": "A NKI 15/20 measures 15 mm bore/Fw × 27 mm outside diameter × 20 mm width (0.591 × 1.063 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.5 kN, static C0 25.5 kN, fatigue limit Pu 3.05 kN, limiting speed 24,000 r/min, reference speed 20,000 r/min, mass about 49 g."
      },
      {
        "q": "What does NKI 15/20 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 15 mm bore, 20 mm width, 27 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI15-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI15-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×27×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI15-20",
      "NKI 15/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4902",
    "brand": "SKF",
    "manufacturer_designation": "NA 4902",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.2,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.83,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4902 measures 15×28×13 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 15 mm d and 13 mm B, the 28 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 34 g at 15×28×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 11.2/15.3 kN ratings are SKF catalogue values for this exact execution (NA 4902); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 11.2/15.3 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4902 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4902 have?",
        "a": "A NA 4902 measures 15 mm bore/Fw × 28 mm outside diameter × 13 mm width (0.591 × 1.102 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.2 kN, static C0 15.3 kN, fatigue limit Pu 1.83 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 34 g."
      },
      {
        "q": "What does NA 4902 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 15 mm bore, 13 mm width, 28 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4902 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4902 carries its own hardened, ground inner ring on a 15 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4902-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4902",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4902",
      "NA 4902"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4902-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4902.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12,
    "fatigue_load_limit_kN": 1.43,
    "max_rpm": 9500,
    "limiting_speed_rpm": 9500,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4902.2RS measures 15×28×14 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The NA 4902.2RS code gives bore 15 mm and width 14 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 15 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 14 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NA 4902.2RS shares its 15×28×14 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 9.13/12 kN ratings and 37 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4902.2RS designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 15 mm bore, 14 mm width, 28 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4902.2RS run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4902.2RS carries its own hardened, ground inner ring on a 15 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4902.2RS be mounted?",
        "a": "Mount the inner ring on the 15 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4902.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4902-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4902",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4902-2RS",
      "NA 4902.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6902",
    "brand": "SKF",
    "manufacturer_designation": "NA 6902",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.2,
    "static_load_kN": 27,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 64,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 6902 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 15 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NA 6902 tells you the envelope — 15×28×23 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NA 6902 shares its 15×28×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 17.2/27 kN ratings and 64 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 6902?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 6902?",
        "a": "A NA 6902 measures 15 mm bore/Fw × 28 mm outside diameter × 23 mm width (0.591 × 1.102 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 17.2 kN, static C0 27 kN, fatigue limit Pu 3.35 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 64 g."
      },
      {
        "q": "How is the NA 6902 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 15 mm bore, 23 mm width, 28 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 6902 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6902 carries its own hardened, ground inner ring on a 15 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6902-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6902",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6902",
      "NA 6902"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS15",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 15",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 30,
    "fatigue_load_limit_kN": 3.65,
    "max_rpm": 19000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 19000,
    "weight_g": 92,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIS 15 provides the full machined-ring needle roller construction: ground inner ring on a 15 mm seat, flanged outer ring at 35 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 15 mm d and 20 mm B, the 35 mm outside diameter from the wide-section machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 16,000 r/min thermal reference and 19,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 15 mm seat. Mounting: heat or press the inner ring onto the 15 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 20 mm assembly for free rotation before applying load.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 35 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 16,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 24.6/30 kN ratings and 92 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKIS 15?",
        "a": "Mount the inner ring on the 15 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKIS 15 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKIS 15 have?",
        "a": "A NKIS 15 measures 15 mm bore/Fw × 35 mm outside diameter × 20 mm width (0.591 × 1.378 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 30 kN, fatigue limit Pu 3.65 kN, limiting speed 19,000 r/min, reference speed 16,000 r/min, mass about 92 g."
      },
      {
        "q": "What does NKIS 15 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 15 mm bore, 20 mm width, 35 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS15-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS15",
      "NKIS 15"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI17-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 17/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 29,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.8,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 2.45,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 17/16 denotes a complete needle roller bearing for a 17 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 29 mm OD and 16 mm width. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 17 mm d and 16 mm B, the 29 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Selection arithmetic: C 13.8 kN against C0 20.4 kN gives a C0/C ratio of 1.48, and the 2.45 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 29 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 13.8/20.4 kN ratings are SKF catalogue values for this exact execution (NKI 17/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 13.8/20.4 kN ratings and 42 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKI 17/16 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 17/16 have?",
        "a": "A NKI 17/16 measures 17 mm bore/Fw × 29 mm outside diameter × 16 mm width (0.669 × 1.142 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.8 kN, static C0 20.4 kN, fatigue limit Pu 2.45 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 42 g."
      },
      {
        "q": "What does NKI 17/16 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 17 mm bore, 16 mm width, 29 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 17/16 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 17/16 carries its own hardened, ground inner ring on a 17 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI17-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NKI17-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI17-16",
      "NKI 17/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI17-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 17/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 29,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 17.2,
    "static_load_kN": 27,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 17 mm shaft that cannot be hardened on site, NKI 17/20 adds a hardened, ground inner ring to the machined needle roller design: envelope 17×29×20 mm per the machined-ring needle roller bearings with inner ring plan. The NKI 17/20 code gives bore 17 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Selection arithmetic: C 17.2 kN against C0 27 kN gives a C0/C ratio of 1.57, and the 3.35 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 17 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 20 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 29 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 17.2/27 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKI 17/20 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 17/20 carries its own hardened, ground inner ring on a 17 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 17/20 be mounted?",
        "a": "Mount the inner ring on the 17 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 17/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 17/20?",
        "a": "A NKI 17/20 measures 17 mm bore/Fw × 29 mm outside diameter × 20 mm width (0.669 × 1.142 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 17.2 kN, static C0 27 kN, fatigue limit Pu 3.35 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 53 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI17-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI17-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×29×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI17-20",
      "NKI 17/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4903",
    "brand": "SKF",
    "manufacturer_designation": "NA 4903",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.4,
    "static_load_kN": 16.3,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 38,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4903 denotes a complete needle roller bearing for a 17 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 30 mm OD and 13 mm width. The designation NA 4903 tells you the envelope — 17×30×13 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 38 g at 17×30×13 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 17 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 11.4/16.3 kN ratings are SKF catalogue values for this exact execution (NA 4903); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 11.4/16.3 kN ratings and 38 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NA 4903 be mounted?",
        "a": "Mount the inner ring on the 17 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4903?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4903?",
        "a": "A NA 4903 measures 17 mm bore/Fw × 30 mm outside diameter × 13 mm width (0.669 × 1.181 × 0.512 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.4 kN, static C0 16.3 kN, fatigue limit Pu 1.96 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 38 g."
      },
      {
        "q": "How is the NA 4903 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 17 mm bore, 13 mm width, 30 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4903-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4903",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4903",
      "NA 4903"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4903-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4903.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.52,
    "static_load_kN": 12.9,
    "fatigue_load_limit_kN": 1.53,
    "max_rpm": 9000,
    "limiting_speed_rpm": 9000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 17 mm shaft that cannot be hardened on site, NA 4903.2RS adds a hardened, ground inner ring to the machined needle roller design: envelope 17×30×14 mm per the dimension series 49 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 17 mm bore (d), 14 mm width; the 30 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. The 40 g catalogue mass and 6.5 mm radial section ((30−17)/2) frame a rating of about 0.56 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4903.2RS shares its 17×30×14 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 9.52/12.9 kN ratings and 40 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 4903.2RS need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4903.2RS carries its own hardened, ground inner ring on a 17 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4903.2RS?",
        "a": "Mount the inner ring on the 17 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4903.2RS sealed?",
        "a": "Yes — the 2RS execution seals both faces with rubber contact seals; note its wider outer ring (B and s differ from the open execution), so housing dimensions must be re-checked."
      },
      {
        "q": "Which dimensions does the NA 4903.2RS have?",
        "a": "A NA 4903.2RS measures 17 mm bore/Fw × 30 mm outside diameter × 14 mm width (0.669 × 1.181 × 0.551 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.52 kN, static C0 12.9 kN, fatigue limit Pu 1.53 kN, limiting speed 9,000 r/min, mass about 40 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4903-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4903",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4903-2RS",
      "NA 4903.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6903",
    "brand": "SKF",
    "manufacturer_designation": "NA 6903",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 18.7,
    "static_load_kN": 30.5,
    "fatigue_load_limit_kN": 3.75,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 72,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 69 needle roller bearings with inner ring execution NA 6903 measures 17×30×23 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 17 mm bore (d), 23 mm width; the 30 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 6903 shares its 17×30×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 18.7/30.5 kN ratings and 72 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 6903?",
        "a": "Mount the inner ring on the 17 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 6903 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 6903 have?",
        "a": "A NA 6903 measures 17 mm bore/Fw × 30 mm outside diameter × 23 mm width (0.669 × 1.181 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 18.7 kN, static C0 30.5 kN, fatigue limit Pu 3.75 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 72 g."
      },
      {
        "q": "What does NA 6903 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 17 mm bore, 23 mm width, 30 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6903-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6903",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6903",
      "NA 6903"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS17",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 17",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 37,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26,
    "static_load_kN": 33.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 98,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 17 mm shaft that cannot be hardened on site, NKIS 17 adds a hardened, ground inner ring to the machined needle roller design: envelope 17×37×20 mm per the wide-section machined-ring needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 17 mm bore (d), 20 mm width; the 37 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 15,000 r/min thermal reference and 17,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 17 mm seat. Mounting: heat or press the inner ring onto the 17 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 20 mm assembly for free rotation before applying load.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIS 17 shares its 17×37×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 26/33.5 kN ratings and 98 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 638); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKIS 17 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 17 mm bore, 20 mm width, 37 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKIS 17 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKIS 17 carries its own hardened, ground inner ring on a 17 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKIS 17?",
        "a": "Mount the inner ring on the 17 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKIS 17 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS17-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×37×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS17",
      "NKIS 17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI20-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 20/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.4,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 2.9,
    "max_rpm": 19000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 19000,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 20/16 in the machined-ring needle roller bearings with inner ring with boundary dimensions 20×32×16 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 20 mm d and 16 mm B, the 32 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. For life calculation, the 15.4/24.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 16 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 15.4/24.5 kN ratings are SKF catalogue values for this exact execution (NKI 20/16); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 15.4/24.5 kN ratings and 48 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKI 20/16 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 20/16 carries its own hardened, ground inner ring on a 20 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 20/16?",
        "a": "Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 20/16 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 20/16 have?",
        "a": "A NKI 20/16 measures 20 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.787 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.4 kN, static C0 24.5 kN, fatigue limit Pu 2.9 kN, limiting speed 19,000 r/min, reference speed 16,000 r/min, mass about 48 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI20-16-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NKI20-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI20-16",
      "NKI 20/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI20-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 20/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 19000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 19000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 20/20 measures 20×32×20 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The NKI 20/20 code gives bore 20 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. For life calculation, the 19/32.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 19/32.5 kN ratings and 60 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 20/20?",
        "a": "A NKI 20/20 measures 20 mm bore/Fw × 32 mm outside diameter × 20 mm width (0.787 × 1.26 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 19,000 r/min, reference speed 16,000 r/min, mass about 60 g."
      },
      {
        "q": "How is the NKI 20/20 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 20 mm bore, 20 mm width, 32 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 20/20 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 20/20 carries its own hardened, ground inner ring on a 20 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 20/20 be mounted?",
        "a": "Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI20-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI20-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKS20",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×20 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 23.3/27 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI20-20",
      "NKI 20/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4904",
    "brand": "SKF",
    "manufacturer_designation": "NA 4904",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 28,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 75,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4904 provides the full machined-ring needle roller construction: ground inner ring on a 20 mm seat, flanged outer ring at 37 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 20 mm bore (d), 17 mm width; the 37 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 75 g at 20×37×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 20 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 21.6/28 kN ratings and 75 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 4904 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4904 carries its own hardened, ground inner ring on a 20 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4904?",
        "a": "Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4904 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4904 have?",
        "a": "A NA 4904 measures 20 mm bore/Fw × 37 mm outside diameter × 17 mm width (0.787 × 1.457 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 28 kN, fatigue limit Pu 3.35 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 75 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4904-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NA4904",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4904",
      "NA 4904"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4904-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4904.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19.4,
    "static_load_kN": 22.4,
    "fatigue_load_limit_kN": 2.65,
    "max_rpm": 7500,
    "limiting_speed_rpm": 7500,
    "weight_g": 80,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4904.2RS provides the full machined-ring needle roller construction: ground inner ring on a 20 mm seat, flanged outer ring at 37 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 20 mm bore (d), 18 mm width; the 37 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 80 g at 20×37×18 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 18 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 19.4/22.4 kN ratings are SKF catalogue values for this exact execution (NA 4904.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 19.4/22.4 kN ratings and 80 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 4904.2RS?",
        "a": "Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4904.2RS sealed?",
        "a": "Yes — the 2RS execution seals both faces with rubber contact seals; note its wider outer ring (B and s differ from the open execution), so housing dimensions must be re-checked."
      },
      {
        "q": "Which dimensions does the NA 4904.2RS have?",
        "a": "A NA 4904.2RS measures 20 mm bore/Fw × 37 mm outside diameter × 18 mm width (0.787 × 1.457 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19.4 kN, static C0 22.4 kN, fatigue limit Pu 2.65 kN, limiting speed 7,500 r/min, mass about 80 g."
      },
      {
        "q": "What does NA 4904.2RS mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 20 mm bore, 18 mm width, 37 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4904-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4904",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4904-2RS",
      "NA 4904.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6904",
    "brand": "SKF",
    "manufacturer_designation": "NA 6904",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 35.2,
    "static_load_kN": 53,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 6904 denotes a complete needle roller bearing for a 20 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 37 mm OD and 30 mm width. The NA 6904 code gives bore 20 mm and width 30 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 35.2/53 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 6904 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6904 carries its own hardened, ground inner ring on a 20 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 6904 be mounted?",
        "a": "Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 6904?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 6904?",
        "a": "A NA 6904 measures 20 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.787 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 35.2 kN, static C0 53 kN, fatigue limit Pu 6.55 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 140 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6904-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6904",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6904",
      "NA 6904"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS20",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 20",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 28.6,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.75,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The wide-section machined-ring needle roller bearings with inner ring execution NKIS 20 measures 20×42×20 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 20 mm d and 20 mm B, the 42 mm outside diameter from the wide-section machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 13,000 r/min thermal reference and 15,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 20 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 13,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 20 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 28.6/39 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKIS 20 have?",
        "a": "A NKIS 20 measures 20 mm bore/Fw × 42 mm outside diameter × 20 mm width (0.787 × 1.654 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 28.6 kN, static C0 39 kN, fatigue limit Pu 4.75 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 130 g."
      },
      {
        "q": "What does NKIS 20 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 20 mm bore, 20 mm width, 42 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKIS 20 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKIS 20 carries its own hardened, ground inner ring on a 20 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKIS 20?",
        "a": "Mount the inner ring on the 20 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "PNA20-42",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×20 mm envelope, but catalogue C/C0 differ between the executions (28.6/39 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS20",
      "NKIS 20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI22-16",
    "brand": "SKF",
    "manufacturer_designation": "NKI 22/16",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 34,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.7,
    "static_load_kN": 26,
    "fatigue_load_limit_kN": 3.1,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 22/16 provides the full machined-ring needle roller construction: ground inner ring on a 22 mm seat, flanged outer ring at 34 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The designation NKI 22/16 tells you the envelope — 22×34×16 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Speed planning separates the two ceilings: 15,000 r/min thermal reference and 17,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 22 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 34 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKI 22/16 shares its 22×34×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 15.7/26 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKI 22/16 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 22 mm bore, 16 mm width, 34 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 22/16 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 22/16 carries its own hardened, ground inner ring on a 22 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 22/16 be mounted?",
        "a": "Mount the inner ring on the 22 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 22/16?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 22 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI22-16-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×34×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI22-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI22",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI22-16",
      "NKI 22/16"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI22-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 22/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 34,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19.4,
    "static_load_kN": 34.5,
    "fatigue_load_limit_kN": 4.25,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 65,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 22/20 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 22 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 22 mm d and 20 mm B, the 34 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Speed planning separates the two ceilings: 15,000 r/min thermal reference and 17,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 22 mm seat. Mounting: heat or press the inner ring onto the 22 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 20 mm assembly for free rotation before applying load.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 34 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 15,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 19.4/34.5 kN ratings and 65 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKI 22/20 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 22/20 have?",
        "a": "A NKI 22/20 measures 22 mm bore/Fw × 34 mm outside diameter × 20 mm width (0.866 × 1.339 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19.4 kN, static C0 34.5 kN, fatigue limit Pu 4.25 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 65 g."
      },
      {
        "q": "What does NKI 22/20 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 22 mm bore, 20 mm width, 34 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 22/20 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 22/20 carries its own hardened, ground inner ring on a 22 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI22-16-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI22-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×34×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI22",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI22-20",
      "NKI 22/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA49-22",
    "brand": "SKF",
    "manufacturer_designation": "NA 49/22",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 39,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.9,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 80,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 22 mm shaft that cannot be hardened on site, NA 49/22 adds a hardened, ground inner ring to the machined needle roller design: envelope 22×39×17 mm per the dimension series 49 needle roller bearings with inner ring plan. The designation NA 49/22 tells you the envelope — 22×39×17 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 22 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 17 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 39 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 22 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 23.3/32 kN ratings are SKF catalogue values for this exact execution (NA 49/22); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 23.3/32 kN ratings and 80 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 49/22 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 49/22 carries its own hardened, ground inner ring on a 22 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 49/22 be mounted?",
        "a": "Mount the inner ring on the 22 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 49/22?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 22 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 49/22?",
        "a": "A NA 49/22 measures 22 mm bore/Fw × 39 mm outside diameter × 17 mm width (0.866 × 1.535 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 32 kN, fatigue limit Pu 3.9 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 80 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA49-22-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×39×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA49-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA49-32-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA49",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA49-22",
      "NA 49/22"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA69-22",
    "brand": "SKF",
    "manufacturer_designation": "NA 69/22",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 39,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.2,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 69 needle roller bearings with inner ring execution NA 69/22 measures 22×39×30 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 22 mm d and 30 mm B, the 39 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 39 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 69/22 shares its 22×39×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 36.9/57 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 69/22?",
        "a": "Mount the inner ring on the 22 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 69/22 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 69/22 have?",
        "a": "A NA 69/22 measures 22 mm bore/Fw × 39 mm outside diameter × 30 mm width (0.866 × 1.535 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 36.9 kN, static C0 57 kN, fatigue limit Pu 7.2 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 150 g."
      },
      {
        "q": "What does NA 69/22 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 22 mm bore, 30 mm width, 39 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA69-22-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 22×39×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA69-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA69-32-ZW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA69",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA69-22",
      "NA 69/22"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI25-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 25/20 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 38,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 42.5,
    "fatigue_load_limit_kN": 5.2,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 80,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 25/20 TN is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 25 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 25 mm d and 20 mm B, the 38 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Speed planning separates the two ceilings: 14,000 r/min thermal reference and 15,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 25 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 38 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 24.6/42.5 kN ratings are SKF catalogue values for this exact execution (NKI 25/20 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 24.6/42.5 kN ratings and 80 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKI 25/20 TN sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 25/20 TN have?",
        "a": "A NKI 25/20 TN measures 25 mm bore/Fw × 38 mm outside diameter × 20 mm width (0.984 × 1.496 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 42.5 kN, fatigue limit Pu 5.2 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 80 g."
      },
      {
        "q": "What does NKI 25/20 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 25 mm bore, 20 mm width, 38 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 25/20 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 25/20 TN carries its own hardened, ground inner ring on a 25 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI25-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×38×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI25-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKS25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×38×20 mm envelope, but catalogue C/C0 differ between the executions (24.6/42.5 vs 27.5/36 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI25-20-TN",
      "NKI 25/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI25-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 25/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 38,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 25/30 measures 25×38×30 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 25 mm bore (d), 30 mm width; the 38 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Selection arithmetic: C 31.9 kN against C0 60 kN gives a C0/C ratio of 1.88, and the 7.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 38 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 14,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 31.9/60 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKI 25/30 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 25 mm bore, 30 mm width, 38 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 25/30 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 25/30 carries its own hardened, ground inner ring on a 25 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 25/30?",
        "a": "Mount the inner ring on the 25 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 25/30 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI25-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI25-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×38×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI25-30",
      "NKI 25/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4905",
    "brand": "SKF",
    "manufacturer_designation": "NA 4905",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 34.5,
    "fatigue_load_limit_kN": 4.15,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 88,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4905 in the dimension series 49 needle roller bearings with inner ring with boundary dimensions 25×42×17 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NA 4905 code gives bore 25 mm and width 17 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 88 g at 25×42×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NA 4905 shares its 25×42×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 13,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 24.2/34.5 kN ratings and 88 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4905 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 25 mm bore, 17 mm width, 42 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4905 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4905 carries its own hardened, ground inner ring on a 25 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4905 be mounted?",
        "a": "Mount the inner ring on the 25 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4905?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4905-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NA4905",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4905",
      "NA 4905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4905-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4905.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 27.5,
    "fatigue_load_limit_kN": 3.25,
    "max_rpm": 6300,
    "limiting_speed_rpm": 6300,
    "weight_g": 90,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4905.2RS measures 25×42×18 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The designation NA 4905.2RS tells you the envelope — 25×42×18 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. For life calculation, the 21.6/27.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: heat or press the inner ring onto the 25 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 18 mm assembly for free rotation before applying load.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 21.6/27.5 kN ratings are SKF catalogue values for this exact execution (NA 4905.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 21.6/27.5 kN ratings and 90 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 4905.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4905.2RS?",
        "a": "A NA 4905.2RS measures 25 mm bore/Fw × 42 mm outside diameter × 18 mm width (0.984 × 1.654 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 27.5 kN, fatigue limit Pu 3.25 kN, limiting speed 6,300 r/min, mass about 90 g."
      },
      {
        "q": "How is the NA 4905.2RS designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 25 mm bore, 18 mm width, 42 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4905.2RS run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4905.2RS carries its own hardened, ground inner ring on a 25 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4905-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4905",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4905-2RS",
      "NA 4905.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6905",
    "brand": "SKF",
    "manufacturer_designation": "NA 6905",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 62,
    "fatigue_load_limit_kN": 7.65,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 6905 provides the full machined-ring needle roller construction: ground inner ring on a 25 mm seat, flanged outer ring at 42 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 25 mm d and 30 mm B, the 42 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 38/62 kN ratings are SKF catalogue values for this exact execution (NA 6905); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 38/62 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 6905 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 25 mm bore, 30 mm width, 42 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 6905 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6905 carries its own hardened, ground inner ring on a 25 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 6905?",
        "a": "Mount the inner ring on the 25 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 6905 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6905-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6905",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6905",
      "NA 6905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS25",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 25",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 47,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 34.1,
    "static_load_kN": 46.5,
    "fatigue_load_limit_kN": 5.7,
    "max_rpm": 13000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 13000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIS 25 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 25 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NKIS 25 tells you the envelope — 25×47×22 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 12,000 r/min thermal reference and 13,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 25 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 22 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 47 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 34.1/46.5 kN ratings are SKF catalogue values for this exact execution (NKIS 25); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 34.1/46.5 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKIS 25?",
        "a": "A NKIS 25 measures 25 mm bore/Fw × 47 mm outside diameter × 22 mm width (0.984 × 1.85 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 34.1 kN, static C0 46.5 kN, fatigue limit Pu 5.7 kN, limiting speed 13,000 r/min, reference speed 12,000 r/min, mass about 160 g."
      },
      {
        "q": "How is the NKIS 25 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 25 mm bore, 22 mm width, 47 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKIS 25 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKIS 25 carries its own hardened, ground inner ring on a 25 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKIS 25 be mounted?",
        "a": "Mount the inner ring on the 25 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×47×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS25",
      "NKIS 25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI28-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 28/20 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 48,
    "fatigue_load_limit_kN": 6,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 92,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 28/20 TN denotes a complete needle roller bearing for a 28 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 42 mm OD and 20 mm width. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 28 mm bore (d), 20 mm width; the 42 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. The 92 g catalogue mass and 7.0 mm radial section ((42−28)/2) frame a rating of about 0.94 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 12,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 28 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 26.4/48 kN ratings and 92 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKI 28/20 TN sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 28/20 TN have?",
        "a": "A NKI 28/20 TN measures 28 mm bore/Fw × 42 mm outside diameter × 20 mm width (1.102 × 1.654 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 48 kN, fatigue limit Pu 6 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 92 g."
      },
      {
        "q": "What does NKI 28/20 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 28 mm bore, 20 mm width, 42 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 28/20 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 28/20 TN carries its own hardened, ground inner ring on a 28 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI28-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×42×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI28-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKS28",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 28×42×20 mm envelope, but catalogue C/C0 differ between the executions (26.4/48 vs 28.6/39 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI28-20-TN",
      "NKI 28/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI28-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 28/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 34.1,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 28 mm shaft that cannot be hardened on site, NKI 28/30 adds a hardened, ground inner ring to the machined needle roller design: envelope 28×42×30 mm per the machined-ring needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 28 mm d and 30 mm B, the 42 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. For life calculation, the 34.1/65.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 30 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 28/30 shares its 28×42×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 34.1/65.5 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 28/30 have?",
        "a": "A NKI 28/30 measures 28 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.102 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 34.1 kN, static C0 65.5 kN, fatigue limit Pu 8.3 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 140 g."
      },
      {
        "q": "What does NKI 28/30 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 28 mm bore, 30 mm width, 42 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 28/30 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 28/30 carries its own hardened, ground inner ring on a 28 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 28/30?",
        "a": "Mount the inner ring on the 28 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI28-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI28-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×42×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI28",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI28-30",
      "NKI 28/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA49-28",
    "brand": "SKF",
    "manufacturer_designation": "NA 49/28",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 45,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.1,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 4.4,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 98,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 28 mm shaft that cannot be hardened on site, NA 49/28 adds a hardened, ground inner ring to the machined needle roller design: envelope 28×45×17 mm per the dimension series 49 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 28 mm d and 17 mm B, the 45 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. For life calculation, the 25.1/36.5 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: heat or press the inner ring onto the 28 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 17 mm assembly for free rotation before applying load.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 12,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 28 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 25.1/36.5 kN ratings and 98 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 49/28 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 28 mm bore, 17 mm width, 45 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 49/28 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 49/28 carries its own hardened, ground inner ring on a 28 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 49/28?",
        "a": "Mount the inner ring on the 28 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 49/28 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA49-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA49-28-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NA49-32-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA49",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA49-28",
      "NA 49/28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA69-28",
    "brand": "SKF",
    "manufacturer_designation": "NA 69/28",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 28,
    "D_mm": 45,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.6,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 14000,
    "reference_speed_rpm": 12000,
    "limiting_speed_rpm": 14000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 69 needle roller bearings with inner ring execution NA 69/28 measures 28×45×30 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 28 mm bore (d), 30 mm width; the 45 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 28 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 28 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 69/28 shares its 28×45×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 39.6/65.5 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 69/28 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 69/28 carries its own hardened, ground inner ring on a 28 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 69/28?",
        "a": "Mount the inner ring on the 28 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 69/28 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 69/28 have?",
        "a": "A NA 69/28 measures 28 mm bore/Fw × 45 mm outside diameter × 30 mm width (1.102 × 1.772 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.6 kN, static C0 65.5 kN, fatigue limit Pu 8.3 kN, limiting speed 14,000 r/min, reference speed 12,000 r/min, mass about 180 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA69-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA69-28-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 28×45×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA69-32-ZW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA69",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA69-28",
      "NA 69/28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI30-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 30/20 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 45,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 52,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 30/20 TN denotes a complete needle roller bearing for a 30 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 45 mm OD and 20 mm width. The NKI 30/20 TN code gives bore 30 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NKI 30/20 TN shares its 30×45×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 27.5/52 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 30/20 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 30/20 TN?",
        "a": "A NKI 30/20 TN measures 30 mm bore/Fw × 45 mm outside diameter × 20 mm width (1.181 × 1.772 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 52 kN, fatigue limit Pu 6.55 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 110 g."
      },
      {
        "q": "How is the NKI 30/20 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 30 mm bore, 20 mm width, 45 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 30/20 TN run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 30/20 TN carries its own hardened, ground inner ring on a 30 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI30-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×45×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI30-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI30-20-TN",
      "NKI 30/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI30-30-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 30/30 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 45,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 85,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 30/30 TN is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 30 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 30 mm bore (d), 30 mm width; the 45 mm OD follows the dimension series, and the inner ring is a separate ground component. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. The 170 g catalogue mass and 7.5 mm radial section ((45−30)/2) frame a rating of about 1.34 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: heat or press the inner ring onto the 30 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 30/30 TN shares its 30×45×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 40.2/85 kN ratings and 170 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 30/30 TN have?",
        "a": "A NKI 30/30 TN measures 30 mm bore/Fw × 45 mm outside diameter × 30 mm width (1.181 × 1.772 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 40.2 kN, static C0 85 kN, fatigue limit Pu 10.6 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 170 g."
      },
      {
        "q": "What does NKI 30/30 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 30 mm bore, 30 mm width, 45 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 30/30 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 30/30 TN carries its own hardened, ground inner ring on a 30 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 30/30 TN?",
        "a": "Mount the inner ring on the 30 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI30-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI30-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×45×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI30-30-TN",
      "NKI 30/30 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4906",
    "brand": "SKF",
    "manufacturer_designation": "NA 4906",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.5,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.65,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 30 mm shaft that cannot be hardened on site, NA 4906 adds a hardened, ground inner ring to the machined needle roller design: envelope 30×47×17 mm per the dimension series 49 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 30 mm d and 17 mm B, the 47 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 100 g at 30×47×17 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4906 shares its 30×47×17 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 25.5/39 kN ratings and 100 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 4906 have?",
        "a": "A NA 4906 measures 30 mm bore/Fw × 47 mm outside diameter × 17 mm width (1.181 × 1.85 × 0.669 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 100 g."
      },
      {
        "q": "What does NA 4906 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 30 mm bore, 17 mm width, 47 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4906 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4906 carries its own hardened, ground inner ring on a 30 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4906?",
        "a": "Mount the inner ring on the 30 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4906-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4906",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4906",
      "NA 4906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4906-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4906.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.8,
    "max_rpm": 5600,
    "limiting_speed_rpm": 5600,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 30 mm shaft that cannot be hardened on site, NA 4906.2RS adds a hardened, ground inner ring to the machined needle roller design: envelope 30×47×18 mm per the dimension series 49 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 30 mm d and 18 mm B, the 47 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 23.3 kN against C0 32 kN gives a C0/C ratio of 1.37, and the 3.8 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 30 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 18 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 23.3/32 kN ratings and 100 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4906.2RS sealed?",
        "a": "Yes — the 2RS execution seals both faces with rubber contact seals; note its wider outer ring (B and s differ from the open execution), so housing dimensions must be re-checked."
      },
      {
        "q": "Which dimensions does the NA 4906.2RS have?",
        "a": "A NA 4906.2RS measures 30 mm bore/Fw × 47 mm outside diameter × 18 mm width (1.181 × 1.85 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 32 kN, fatigue limit Pu 3.8 kN, limiting speed 5,600 r/min, mass about 100 g."
      },
      {
        "q": "What does NA 4906.2RS mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 30 mm bore, 18 mm width, 47 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4906.2RS need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4906.2RS carries its own hardened, ground inner ring on a 30 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4906-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4906",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4906-2RS",
      "NA 4906.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6906",
    "brand": "SKF",
    "manufacturer_designation": "NA 6906",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 75,
    "fatigue_load_limit_kN": 9.3,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 6906 in the dimension series 69 needle roller bearings with inner ring with boundary dimensions 30×47×30 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NA 6906 tells you the envelope — 30×47×30 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 42.9/75 kN ratings are SKF catalogue values for this exact execution (NA 6906); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 42.9/75 kN ratings and 190 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 6906?",
        "a": "A NA 6906 measures 30 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.181 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 75 kN, fatigue limit Pu 9.3 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 190 g."
      },
      {
        "q": "How is the NA 6906 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 30 mm bore, 30 mm width, 47 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 6906 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6906 carries its own hardened, ground inner ring on a 30 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 6906 be mounted?",
        "a": "Mount the inner ring on the 30 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6906-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6906",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6906",
      "NA 6906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS30",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 30",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 52,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.55,
    "max_rpm": 12000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 12000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIS 30 in the wide-section machined-ring needle roller bearings with inner ring with boundary dimensions 30×52×22 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NKIS 30 tells you the envelope — 30×52×22 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 10,000 r/min thermal reference and 12,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 30 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 36.9/54 kN ratings are SKF catalogue values for this exact execution (NKIS 30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 36.9/54 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKIS 30 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKIS 30 carries its own hardened, ground inner ring on a 30 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKIS 30 be mounted?",
        "a": "Mount the inner ring on the 30 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKIS 30?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIS 30?",
        "a": "A NKIS 30 measures 30 mm bore/Fw × 52 mm outside diameter × 22 mm width (1.181 × 2.047 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 36.9 kN, static C0 54 kN, fatigue limit Pu 6.55 kN, limiting speed 12,000 r/min, reference speed 10,000 r/min, mass about 180 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×52×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS30",
      "NKIS 30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI32-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 32/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 47,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.1,
    "static_load_kN": 46.5,
    "fatigue_load_limit_kN": 5.85,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 32/20 in the machined-ring needle roller bearings with inner ring with boundary dimensions 32×47×20 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NKI 32/20 code gives bore 32 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 110 g at 32×47×20 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NKI 32/20 shares its 32×47×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 25.1/46.5 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 32/20?",
        "a": "A NKI 32/20 measures 32 mm bore/Fw × 47 mm outside diameter × 20 mm width (1.26 × 1.85 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.1 kN, static C0 46.5 kN, fatigue limit Pu 5.85 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 110 g."
      },
      {
        "q": "How is the NKI 32/20 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 32 mm bore, 20 mm width, 47 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 32/20 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 32/20 carries its own hardened, ground inner ring on a 32 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 32/20 be mounted?",
        "a": "Mount the inner ring on the 32 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI32-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×47×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI32-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI32-20",
      "NKI 32/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI32-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 32/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 76.5,
    "fatigue_load_limit_kN": 9.5,
    "max_rpm": 12000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 12000,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 32/30 measures 32×47×30 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 32 mm d and 30 mm B, the 47 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 170 g at 32×47×30 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 32 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 32 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 36.9/76.5 kN ratings and 170 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKI 32/30 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 32/30 carries its own hardened, ground inner ring on a 32 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 32/30?",
        "a": "Mount the inner ring on the 32 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 32/30 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 32/30 have?",
        "a": "A NKI 32/30 measures 32 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.26 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 36.9 kN, static C0 76.5 kN, fatigue limit Pu 9.5 kN, limiting speed 12,000 r/min, reference speed 11,000 r/min, mass about 170 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI32-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI32-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×47×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI32",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI32-30",
      "NKI 32/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA49-32",
    "brand": "SKF",
    "manufacturer_designation": "NA 49/32",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 52,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 30.8,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 49/32 denotes a complete needle roller bearing for a 32 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 52 mm OD and 20 mm width. The NA 49/32 code gives bore 32 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. For life calculation, the 30.8/51 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 32 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 30.8/51 kN ratings are SKF catalogue values for this exact execution (NA 49/32); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 30.8/51 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 49/32?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 32 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 49/32?",
        "a": "A NA 49/32 measures 32 mm bore/Fw × 52 mm outside diameter × 20 mm width (1.26 × 2.047 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 30.8 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 160 g."
      },
      {
        "q": "How is the NA 49/32 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 32 mm bore, 20 mm width, 52 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 49/32 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 49/32 carries its own hardened, ground inner ring on a 32 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA49-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA49-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA49-32-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×52×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA49",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA49-32",
      "NA 49/32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA69-32",
    "brand": "SKF",
    "manufacturer_designation": "NA 69/32",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 32,
    "D_mm": 52,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 47.3,
    "static_load_kN": 90,
    "fatigue_load_limit_kN": 10.8,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 69/32 in the dimension series 69 needle roller bearings with inner ring with boundary dimensions 32×52×36 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NA 69/32 tells you the envelope — 32×52×36 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 32 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 36 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 32 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 32 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NA 69/32 shares its 32×52×36 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 10,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 47.3/90 kN ratings and 290 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 640); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 69/32?",
        "a": "A NA 69/32 measures 32 mm bore/Fw × 52 mm outside diameter × 36 mm width (1.26 × 2.047 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 47.3 kN, static C0 90 kN, fatigue limit Pu 10.8 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 290 g."
      },
      {
        "q": "How is the NA 69/32 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 32 mm bore, 36 mm width, 52 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 69/32 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 69/32 carries its own hardened, ground inner ring on a 32 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 69/32 be mounted?",
        "a": "Mount the inner ring on the 32 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA69-22-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA69-28-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA69-32-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 32×52×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA69",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA69-32",
      "NA 69/32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI35-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 35/20 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 50,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 29.7,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 35/20 TN is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 35 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NKI 35/20 TN code gives bore 35 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Catalogue mass 120 g at 35×50×20 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 35 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 20 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 29.7/60 kN ratings are SKF catalogue values for this exact execution (NKI 35/20 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 29.7/60 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 35/20 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 35/20 TN?",
        "a": "A NKI 35/20 TN measures 35 mm bore/Fw × 50 mm outside diameter × 20 mm width (1.378 × 1.969 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 29.7 kN, static C0 60 kN, fatigue limit Pu 7.5 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 120 g."
      },
      {
        "q": "How is the NKI 35/20 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 35 mm bore, 20 mm width, 50 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 35/20 TN run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 35/20 TN carries its own hardened, ground inner ring on a 35 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI35-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×50×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI35-20-TW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×50×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI35-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI35-20-TN",
      "NKI 35/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI35-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 35/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 50,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 83,
    "fatigue_load_limit_kN": 10.4,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 35 mm shaft that cannot be hardened on site, NKI 35/30 adds a hardened, ground inner ring to the machined needle roller design: envelope 35×50×30 mm per the machined-ring needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 35 mm bore (d), 30 mm width; the 50 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. For life calculation, the 38/83 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 30 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 35/30 shares its 35×50×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 38/83 kN ratings and 190 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKI 35/30 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 35/30 carries its own hardened, ground inner ring on a 35 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 35/30?",
        "a": "Mount the inner ring on the 35 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 35/30 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 35/30 have?",
        "a": "A NKI 35/30 measures 35 mm bore/Fw × 50 mm outside diameter × 30 mm width (1.378 × 1.969 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 83 kN, fatigue limit Pu 10.4 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 190 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI35-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI35-20-TW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI35-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×50×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI35-30",
      "NKI 35/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4907",
    "brand": "SKF",
    "manufacturer_designation": "NA 4907",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.7,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4907 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 35 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NA 4907 tells you the envelope — 35×55×20 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 170 g at 35×55×20 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 31.9/54 kN ratings and 170 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 4907?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4907?",
        "a": "A NA 4907 measures 35 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.378 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 54 kN, fatigue limit Pu 6.7 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 170 g."
      },
      {
        "q": "How is the NA 4907 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 35 mm bore, 20 mm width, 55 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4907 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4907 carries its own hardened, ground inner ring on a 35 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4907-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "PNA35-55",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×20 mm envelope, but catalogue C/C0 differ between the executions (31.9/54 vs 26.4/51 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4907",
      "NA 4907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4907-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4907.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27,
    "static_load_kN": 43,
    "fatigue_load_limit_kN": 5.3,
    "max_rpm": 4800,
    "limiting_speed_rpm": 4800,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4907.2RS provides the full machined-ring needle roller construction: ground inner ring on a 35 mm seat, flanged outer ring at 55 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 35 mm d and 21 mm B, the 55 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. For life calculation, the 27/43 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4907.2RS shares its 35×55×21 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 27/43 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 4907.2RS have?",
        "a": "A NA 4907.2RS measures 35 mm bore/Fw × 55 mm outside diameter × 21 mm width (1.378 × 2.165 × 0.827 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27 kN, static C0 43 kN, fatigue limit Pu 5.3 kN, limiting speed 4,800 r/min, mass about 180 g."
      },
      {
        "q": "What does NA 4907.2RS mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 35 mm bore, 21 mm width, 55 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4907.2RS need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4907.2RS carries its own hardened, ground inner ring on a 35 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4907.2RS?",
        "a": "Mount the inner ring on the 35 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4907-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4907",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4907-2RS",
      "NA 4907.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6907",
    "brand": "SKF",
    "manufacturer_designation": "NA 6907",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 48.4,
    "static_load_kN": 93,
    "fatigue_load_limit_kN": 11.4,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 35 mm shaft that cannot be hardened on site, NA 6907 adds a hardened, ground inner ring to the machined needle roller design: envelope 35×55×36 mm per the dimension series 69 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 35 mm bore (d), 36 mm width; the 55 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 9,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 48.4/93 kN ratings and 310 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 6907 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 6907 have?",
        "a": "A NA 6907 measures 35 mm bore/Fw × 55 mm outside diameter × 36 mm width (1.378 × 2.165 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 48.4 kN, static C0 93 kN, fatigue limit Pu 11.4 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 310 g."
      },
      {
        "q": "What does NA 6907 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 35 mm bore, 36 mm width, 55 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 6907 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6907 carries its own hardened, ground inner ring on a 35 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6907-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6907",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6907",
      "NA 6907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS35",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 35",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 58,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.1,
    "static_load_kN": 61,
    "fatigue_load_limit_kN": 7.5,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIS 35 provides the full machined-ring needle roller construction: ground inner ring on a 35 mm seat, flanged outer ring at 58 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 35 mm bore (d), 22 mm width; the 58 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 9,000 r/min thermal reference and 10,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 35 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 39.1/61 kN ratings are SKF catalogue values for this exact execution (NKIS 35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 39.1/61 kN ratings and 220 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKIS 35 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKIS 35 carries its own hardened, ground inner ring on a 35 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKIS 35?",
        "a": "Mount the inner ring on the 35 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKIS 35 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKIS 35 have?",
        "a": "A NKIS 35 measures 35 mm bore/Fw × 58 mm outside diameter × 22 mm width (1.378 × 2.283 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.1 kN, static C0 61 kN, fatigue limit Pu 7.5 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 220 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×58×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS35",
      "NKIS 35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI38-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 38/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 38,
    "D_mm": 53,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 55,
    "fatigue_load_limit_kN": 6.8,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 38/20 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 38 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NKI 38/20 code gives bore 38 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Selection arithmetic: C 27.5 kN against C0 55 kN gives a C0/C ratio of 2.00, and the 6.8 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 38 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 38 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 38 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 27.5/55 kN ratings are SKF catalogue values for this exact execution (NKI 38/20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 27.5/55 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 38/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 38 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 38/20?",
        "a": "A NKI 38/20 measures 38 mm bore/Fw × 53 mm outside diameter × 20 mm width (1.496 × 2.087 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 55 kN, fatigue limit Pu 6.8 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 130 g."
      },
      {
        "q": "How is the NKI 38/20 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 38 mm bore, 20 mm width, 53 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 38/20 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 38/20 carries its own hardened, ground inner ring on a 38 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI38-20-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NKI38-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI38",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI38-20",
      "NKI 38/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI38-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 38/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 38,
    "D_mm": 53,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 90,
    "fatigue_load_limit_kN": 11.2,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 210,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 38/30 provides the full machined-ring needle roller construction: ground inner ring on a 38 mm seat, flanged outer ring at 53 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 38 mm d and 30 mm B, the 53 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Selection arithmetic: C 40.2 kN against C0 90 kN gives a C0/C ratio of 2.24, and the 11.2 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 38 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 38 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 38 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 40.2/90 kN ratings are SKF catalogue values for this exact execution (NKI 38/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 40.2/90 kN ratings and 210 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKI 38/30 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 38 mm bore, 30 mm width, 53 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 38/30 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 38/30 carries its own hardened, ground inner ring on a 38 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 38/30?",
        "a": "Mount the inner ring on the 38 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 38/30 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI38-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI38-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 38×53×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI38",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI38-30",
      "NKI 38/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI40-20-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 40/20 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 31.4,
    "static_load_kN": 65.5,
    "fatigue_load_limit_kN": 8.3,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 40/20 TN denotes a complete needle roller bearing for a 40 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 55 mm OD and 20 mm width. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 40 mm bore (d), 20 mm width; the 55 mm OD follows the dimension series, and the inner ring is a separate ground component. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. The 140 g catalogue mass and 7.5 mm radial section ((55−40)/2) frame a rating of about 0.78 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 40/20 TN shares its 40×55×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 31.4/65.5 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKI 40/20 TN sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 40/20 TN have?",
        "a": "A NKI 40/20 TN measures 40 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.575 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.4 kN, static C0 65.5 kN, fatigue limit Pu 8.3 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 140 g."
      },
      {
        "q": "What does NKI 40/20 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 40 mm bore, 20 mm width, 55 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 40/20 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 40/20 TN carries its own hardened, ground inner ring on a 40 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI40-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×55×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI40-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI40-30-TW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "RPNA40-55",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×55×20 mm envelope, but catalogue C/C0 differ between the executions (31.4/65.5 vs 26.4/51 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI40-20-TN",
      "NKI 40/20 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI40-30-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 40/30 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 55,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 45.7,
    "static_load_kN": 108,
    "fatigue_load_limit_kN": 13.7,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 40/30 TN is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 40 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NKI 40/30 TN tells you the envelope — 40×55×30 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Selection arithmetic: C 45.7 kN against C0 108 kN gives a C0/C ratio of 2.36, and the 13.7 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 30 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 45.7/108 kN ratings and 220 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 40/30 TN?",
        "a": "A NKI 40/30 TN measures 40 mm bore/Fw × 55 mm outside diameter × 30 mm width (1.575 × 2.165 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 45.7 kN, static C0 108 kN, fatigue limit Pu 13.7 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 220 g."
      },
      {
        "q": "How is the NKI 40/30 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 40 mm bore, 30 mm width, 55 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 40/30 TN run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 40/30 TN carries its own hardened, ground inner ring on a 40 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 40/30 TN be mounted?",
        "a": "Mount the inner ring on the 40 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI40-20-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI40-30-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×55×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI40-30-TW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×55×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI40",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI40-30-TN",
      "NKI 40/30 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4908",
    "brand": "SKF",
    "manufacturer_designation": "NA 4908",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 71,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 230,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4908 measures 40×62×22 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 40 mm bore (d), 22 mm width; the 62 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 230 g at 40×62×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 42.9/71 kN ratings are SKF catalogue values for this exact execution (NA 4908); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 42.9/71 kN ratings and 230 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 4908?",
        "a": "Mount the inner ring on the 40 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4908 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4908 have?",
        "a": "A NA 4908 measures 40 mm bore/Fw × 62 mm outside diameter × 22 mm width (1.575 × 2.441 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 71 kN, fatigue limit Pu 8.8 kN, limiting speed 9,500 r/min, reference speed 8,000 r/min, mass about 230 g."
      },
      {
        "q": "What does NA 4908 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 40 mm bore, 22 mm width, 62 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4908-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4908",
      "NA 4908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4908-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4908.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 36.9,
    "static_load_kN": 58.5,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 4000,
    "limiting_speed_rpm": 4000,
    "weight_g": 250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4908.2RS measures 40×62×23 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The NA 4908.2RS code gives bore 40 mm and width 23 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 4,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 40 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 23 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 36.9/58.5 kN ratings and 250 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4908.2RS designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 40 mm bore, 23 mm width, 62 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4908.2RS run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4908.2RS carries its own hardened, ground inner ring on a 40 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4908.2RS be mounted?",
        "a": "Mount the inner ring on the 40 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4908.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4908-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4908",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4908-2RS",
      "NA 4908.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6908",
    "brand": "SKF",
    "manufacturer_designation": "NA 6908",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 67.1,
    "static_load_kN": 125,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 6908 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 40 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NA 6908 code gives bore 40 mm and width 40 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NA 6908 shares its 40×62×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 67.1/125 kN ratings and 430 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NA 6908 be mounted?",
        "a": "Mount the inner ring on the 40 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 6908?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 6908?",
        "a": "A NA 6908 measures 40 mm bore/Fw × 62 mm outside diameter × 40 mm width (1.575 × 2.441 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 67.1 kN, static C0 125 kN, fatigue limit Pu 15.3 kN, limiting speed 9,500 r/min, reference speed 8,000 r/min, mass about 430 g."
      },
      {
        "q": "How is the NA 6908 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 40 mm bore, 40 mm width, 62 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6908-ZW-XL",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "NA6908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6908",
      "NA 6908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS40",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 40",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 65,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 72,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 280,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The wide-section machined-ring needle roller bearings with inner ring execution NKIS 40 measures 40×65×22 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 40 mm bore (d), 22 mm width; the 65 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 8,000 r/min thermal reference and 9,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 40 mm seat. Mounting: heat or press the inner ring onto the 40 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 22 mm assembly for free rotation before applying load.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 42.9/72 kN ratings are SKF catalogue values for this exact execution (NKIS 40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 42.9/72 kN ratings and 280 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKIS 40 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKIS 40 have?",
        "a": "A NKIS 40 measures 40 mm bore/Fw × 65 mm outside diameter × 22 mm width (1.575 × 2.559 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 72 kN, fatigue limit Pu 8.8 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 280 g."
      },
      {
        "q": "What does NKIS 40 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 40 mm bore, 22 mm width, 65 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKIS 40 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKIS 40 carries its own hardened, ground inner ring on a 40 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS40-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×65×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS40",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS40",
      "NKIS 40"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI42-20",
    "brand": "SKF",
    "manufacturer_designation": "NKI 42/20",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 57,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 29.2,
    "static_load_kN": 61,
    "fatigue_load_limit_kN": 7.65,
    "max_rpm": 10000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 10000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 42/20 denotes a complete needle roller bearing for a 42 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 57 mm OD and 20 mm width. The NKI 42/20 code gives bore 42 mm and width 20 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 140 g catalogue mass and 7.5 mm radial section ((57−42)/2) frame a rating of about 0.70 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 20 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 29.2/61 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKI 42/20 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 42 mm bore, 20 mm width, 57 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 42/20 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 42/20 carries its own hardened, ground inner ring on a 42 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 42/20 be mounted?",
        "a": "Mount the inner ring on the 42 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 42/20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 42 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI42-20-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 42×57×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI42-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI42",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI42-20",
      "NKI 42/20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI42-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 42/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 42,
    "D_mm": 57,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 41.8,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.5,
    "max_rpm": 10000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 10000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 42 mm shaft that cannot be hardened on site, NKI 42/30 adds a hardened, ground inner ring to the machined needle roller design: envelope 42×57×30 mm per the machined-ring needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 42 mm d and 30 mm B, the 57 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 220 g catalogue mass and 7.5 mm radial section ((57−42)/2) frame a rating of about 1.00 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 42 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 42 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 42/30 shares its 42×57×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 41.8/98 kN ratings and 220 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 42/30?",
        "a": "Mount the inner ring on the 42 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 42/30 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 42/30 have?",
        "a": "A NKI 42/30 measures 42 mm bore/Fw × 57 mm outside diameter × 30 mm width (1.654 × 2.244 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 41.8 kN, static C0 98 kN, fatigue limit Pu 12.5 kN, limiting speed 10,000 r/min, reference speed 8,500 r/min, mass about 220 g."
      },
      {
        "q": "What does NKI 42/30 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 42 mm bore, 30 mm width, 57 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI42-20-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI42-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 42×57×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI42",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI42-30",
      "NKI 42/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI45-25-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 45/25 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 62,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 91.5,
    "fatigue_load_limit_kN": 11.2,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 45/25 TN in the machined-ring needle roller bearings with inner ring with boundary dimensions 45×62×25 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 45 mm d and 25 mm B, the 62 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Selection arithmetic: C 42.9 kN against C0 91.5 kN gives a C0/C ratio of 2.13, and the 11.2 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 25 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 42.9/91.5 kN ratings are SKF catalogue values for this exact execution (NKI 45/25 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 42.9/91.5 kN ratings and 220 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 45/25 TN?",
        "a": "Mount the inner ring on the 45 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 45/25 TN sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 45/25 TN have?",
        "a": "A NKI 45/25 TN measures 45 mm bore/Fw × 62 mm outside diameter × 25 mm width (1.772 × 2.441 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 91.5 kN, fatigue limit Pu 11.2 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 220 g."
      },
      {
        "q": "What does NKI 45/25 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 45 mm bore, 25 mm width, 62 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI45-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×62×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI45-35-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI45-25-TN",
      "NKI 45/25 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI45-35-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 45/35 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 62,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 58.3,
    "static_load_kN": 137,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 45/35 TN denotes a complete needle roller bearing for a 45 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 62 mm OD and 35 mm width. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 45 mm d and 35 mm B, the 62 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. For life calculation, the 58.3/137 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: heat or press the inner ring onto the 45 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 35 mm assembly for free rotation before applying load.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 45 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 58.3/137 kN ratings and 310 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKI 45/35 TN sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 45/35 TN have?",
        "a": "A NKI 45/35 TN measures 45 mm bore/Fw × 62 mm outside diameter × 35 mm width (1.772 × 2.441 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 58.3 kN, static C0 137 kN, fatigue limit Pu 17 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 310 g."
      },
      {
        "q": "What does NKI 45/35 TN mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 45 mm bore, 35 mm width, 62 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 45/35 TN need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 45/35 TN carries its own hardened, ground inner ring on a 45 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI45-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI45-35-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×62×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI45-35-TN",
      "NKI 45/35 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4909",
    "brand": "SKF",
    "manufacturer_designation": "NA 4909",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 45.7,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4909 denotes a complete needle roller bearing for a 45 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 68 mm OD and 22 mm width. The NA 4909 code gives bore 45 mm and width 22 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 270 g at 45×68×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 45 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 45.7/78 kN ratings are SKF catalogue values for this exact execution (NA 4909); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 45.7/78 kN ratings and 270 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 4909 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4909 carries its own hardened, ground inner ring on a 45 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4909 be mounted?",
        "a": "Mount the inner ring on the 45 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4909?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4909?",
        "a": "A NA 4909 measures 45 mm bore/Fw × 68 mm outside diameter × 22 mm width (1.772 × 2.677 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 45.7 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 270 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4909-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×68×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4909",
      "NA 4909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4909-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4909.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 39.1,
    "static_load_kN": 64,
    "fatigue_load_limit_kN": 7.8,
    "max_rpm": 3800,
    "limiting_speed_rpm": 3800,
    "weight_g": 290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 45 mm shaft that cannot be hardened on site, NA 4909.2RS adds a hardened, ground inner ring to the machined needle roller design: envelope 45×68×23 mm per the dimension series 49 needle roller bearings with inner ring plan. The NA 4909.2RS code gives bore 45 mm and width 23 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 45 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 23 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 45 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 39.1/64 kN ratings are SKF catalogue values for this exact execution (NA 4909.2RS); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 39.1/64 kN ratings and 290 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 4909.2RS run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4909.2RS carries its own hardened, ground inner ring on a 45 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4909.2RS be mounted?",
        "a": "Mount the inner ring on the 45 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4909.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4909.2RS?",
        "a": "A NA 4909.2RS measures 45 mm bore/Fw × 68 mm outside diameter × 23 mm width (1.772 × 2.677 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 39.1 kN, static C0 64 kN, fatigue limit Pu 7.8 kN, limiting speed 3,800 r/min, mass about 290 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4909-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4909",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4909-2RS",
      "NA 4909.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6909",
    "brand": "SKF",
    "manufacturer_designation": "NA 6909",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 70.4,
    "static_load_kN": 137,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 69 needle roller bearings with inner ring execution NA 6909 measures 45×68×40 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 45 mm d and 40 mm B, the 68 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 6909 shares its 45×68×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 70.4/137 kN ratings and 500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 6909 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6909 carries its own hardened, ground inner ring on a 45 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 6909?",
        "a": "Mount the inner ring on the 45 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 6909 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 6909 have?",
        "a": "A NA 6909 measures 45 mm bore/Fw × 68 mm outside diameter × 40 mm width (1.772 × 2.677 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 70.4 kN, static C0 137 kN, fatigue limit Pu 17 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6909-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×68×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6909",
      "NA 6909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS45",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 45",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 72,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44.6,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.8,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIS 45 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 45 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NKIS 45 code gives bore 45 mm and width 22 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 7,000 r/min thermal reference and 8,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 45 mm seat. Mounting: heat or press the inner ring onto the 45 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 22 mm assembly for free rotation before applying load.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 44.6/78 kN ratings and 340 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKIS 45?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 13.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIS 45?",
        "a": "A NKIS 45 measures 45 mm bore/Fw × 72 mm outside diameter × 22 mm width (1.772 × 2.835 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44.6 kN, static C0 78 kN, fatigue limit Pu 9.8 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 340 g."
      },
      {
        "q": "How is the NKIS 45 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 45 mm bore, 22 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKIS 45 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKIS 45 carries its own hardened, ground inner ring on a 45 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS45-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 45×72×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS45",
      "NKIS 45"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI50-25",
    "brand": "SKF",
    "manufacturer_designation": "NKI 50/25",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 68,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 88,
    "fatigue_load_limit_kN": 10.8,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 50/25 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 50 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 50 mm bore (d), 25 mm width; the 68 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Speed planning separates the two ceilings: 7,500 r/min thermal reference and 8,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 50 mm seat. Mounting: heat or press the inner ring onto the 50 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 40.2/88 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKI 50/25 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 50/25 carries its own hardened, ground inner ring on a 50 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 50/25?",
        "a": "Mount the inner ring on the 50 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 50/25 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 50/25 have?",
        "a": "A NKI 50/25 measures 50 mm bore/Fw × 68 mm outside diameter × 25 mm width (1.969 × 2.677 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 40.2 kN, static C0 88 kN, fatigue limit Pu 10.8 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 260 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI50-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×68×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI50-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI50",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI50-25",
      "NKI 50/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI50-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 50/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 68,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 52.3,
    "static_load_kN": 122,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 50/35 provides the full machined-ring needle roller construction: ground inner ring on a 50 mm seat, flanged outer ring at 68 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The NKI 50/35 code gives bore 50 mm and width 35 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Speed planning separates the two ceilings: 7,500 r/min thermal reference and 8,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 50 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 35 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 52.3/122 kN ratings are SKF catalogue values for this exact execution (NKI 50/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 52.3/122 kN ratings and 360 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 50/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 9.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 50/35?",
        "a": "A NKI 50/35 measures 50 mm bore/Fw × 68 mm outside diameter × 35 mm width (1.969 × 2.677 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 52.3 kN, static C0 122 kN, fatigue limit Pu 15.3 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 360 g."
      },
      {
        "q": "How is the NKI 50/35 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 50 mm bore, 35 mm width, 68 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 50/35 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 50/35 carries its own hardened, ground inner ring on a 50 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI50-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI50-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×68×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI50",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI50-35",
      "NKI 50/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4910",
    "brand": "SKF",
    "manufacturer_designation": "NA 4910",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 47.3,
    "static_load_kN": 85,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4910 denotes a complete needle roller bearing for a 50 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 72 mm OD and 22 mm width. The NA 4910 code gives bore 50 mm and width 22 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 270 g at 50×72×22 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 50 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 22 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NA 4910 shares its 50×72×22 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 7,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 47.3/85 kN ratings and 270 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NA 4910 be mounted?",
        "a": "Mount the inner ring on the 50 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4910?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4910?",
        "a": "A NA 4910 measures 50 mm bore/Fw × 72 mm outside diameter × 22 mm width (1.969 × 2.835 × 0.866 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 47.3 kN, static C0 85 kN, fatigue limit Pu 10.6 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 270 g."
      },
      {
        "q": "How is the NA 4910 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 50 mm bore, 22 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4910-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×72×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4910",
      "NA 4910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4910-2RS",
    "brand": "SKF",
    "manufacturer_designation": "NA 4910.2RS",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 40.2,
    "static_load_kN": 69.5,
    "fatigue_load_limit_kN": 8.5,
    "max_rpm": 3400,
    "limiting_speed_rpm": 3400,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4910.2RS denotes a complete needle roller bearing for a 50 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 72 mm OD and 23 mm width. The NA 4910.2RS code gives bore 50 mm and width 23 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Speed planning separates the two ceilings: no reference speed listed for this sealed/slow execution and 3,400 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 50 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 23 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NA 4910.2RS shares its 50×72×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the catalogue lists no reference speed for this execution, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 40.2/69.5 kN ratings and 300 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4910.2RS designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 50 mm bore, 23 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4910.2RS run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4910.2RS carries its own hardened, ground inner ring on a 50 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4910.2RS be mounted?",
        "a": "Mount the inner ring on the 50 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4910.2RS?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4910-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4910",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4910-2RS",
      "NA 4910.2RS"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6910",
    "brand": "SKF",
    "manufacturer_designation": "NA 6910",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 73.7,
    "static_load_kN": 150,
    "fatigue_load_limit_kN": 18.6,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 69 needle roller bearings with inner ring execution NA 6910 measures 50×72×40 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 50 mm d and 40 mm B, the 72 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 50 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 40 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 73.7/150 kN ratings are SKF catalogue values for this exact execution (NA 6910); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 73.7/150 kN ratings and 520 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 6910?",
        "a": "Mount the inner ring on the 50 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 6910 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 6910 have?",
        "a": "A NA 6910 measures 50 mm bore/Fw × 72 mm outside diameter × 40 mm width (1.969 × 2.835 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 73.7 kN, static C0 150 kN, fatigue limit Pu 18.6 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 520 g."
      },
      {
        "q": "What does NA 6910 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 50 mm bore, 40 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6910-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×72×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6910",
      "NA 6910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS50",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 50",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 62.7,
    "static_load_kN": 104,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 7500,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7500,
    "weight_g": 520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIS 50 in the wide-section machined-ring needle roller bearings with inner ring with boundary dimensions 50×80×28 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NKIS 50 code gives bore 50 mm and width 28 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 6,300 r/min thermal reference and 7,500 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 50 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 28 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 62.7/104 kN ratings and 520 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKIS 50 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 50 mm bore, 28 mm width, 80 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKIS 50 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKIS 50 carries its own hardened, ground inner ring on a 50 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKIS 50 be mounted?",
        "a": "Mount the inner ring on the 50 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKIS 50?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS50-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 50×80×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS50",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS50",
      "NKIS 50"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI55-25-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKI 55/25 TN",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 46.8,
    "static_load_kN": 110,
    "fatigue_load_limit_kN": 13.4,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 55 mm shaft that cannot be hardened on site, NKI 55/25 TN adds a hardened, ground inner ring to the machined needle roller design: envelope 55×72×25 mm per the machined-ring needle roller bearings with inner ring plan. The NKI 55/25 TN code gives bore 55 mm and width 25 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 55 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 46.8/110 kN ratings are SKF catalogue values for this exact execution (NKI 55/25 TN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 46.8/110 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKI 55/25 TN be mounted?",
        "a": "Mount the inner ring on the 55 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 55/25 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 55/25 TN?",
        "a": "A NKI 55/25 TN measures 55 mm bore/Fw × 72 mm outside diameter × 25 mm width (2.165 × 2.835 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 46.8 kN, static C0 110 kN, fatigue limit Pu 13.4 kN, limiting speed 7,500 r/min, reference speed 6,700 r/min, mass about 260 g."
      },
      {
        "q": "How is the NKI 55/25 TN designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 55 mm bore, 25 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI55-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×72×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI55-25-TW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×72×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI55-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI55",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI55-25-TN",
      "NKI 55/25 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI55-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 55/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 55,
    "static_load_kN": 134,
    "fatigue_load_limit_kN": 17,
    "max_rpm": 7500,
    "reference_speed_rpm": 6700,
    "limiting_speed_rpm": 7500,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 55/35 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 55 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 55 mm bore (d), 35 mm width; the 72 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. For life calculation, the 55/134 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: heat or press the inner ring onto the 55 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 35 mm assembly for free rotation before applying load.",
    "applications": [
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 55/134 kN ratings are SKF catalogue values for this exact execution (NKI 55/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 55/134 kN ratings and 360 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 55/35?",
        "a": "Mount the inner ring on the 55 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 55/35 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 55/35 have?",
        "a": "A NKI 55/35 measures 55 mm bore/Fw × 72 mm outside diameter × 35 mm width (2.165 × 2.835 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 55 kN, static C0 134 kN, fatigue limit Pu 17 kN, limiting speed 7,500 r/min, reference speed 6,700 r/min, mass about 360 g."
      },
      {
        "q": "What does NKI 55/35 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 55 mm bore, 35 mm width, 72 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI55-25-TV-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI55-25-TW-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI55-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×72×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI55",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI55-35",
      "NKI 55/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4911",
    "brand": "SKF",
    "manufacturer_designation": "NA 4911",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 57.2,
    "static_load_kN": 106,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4911 provides the full machined-ring needle roller construction: ground inner ring on a 55 mm seat, flanged outer ring at 80 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 55 mm d and 25 mm B, the 80 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 390 g at 55×80×25 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 55 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4911 shares its 55×80×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 57.2/106 kN ratings and 390 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 4911 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4911 carries its own hardened, ground inner ring on a 55 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4911?",
        "a": "Mount the inner ring on the 55 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4911 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4911 have?",
        "a": "A NA 4911 measures 55 mm bore/Fw × 80 mm outside diameter × 25 mm width (2.165 × 3.15 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 57.2 kN, static C0 106 kN, fatigue limit Pu 13.2 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 390 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4911-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4911",
      "NA 4911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6911",
    "brand": "SKF",
    "manufacturer_designation": "NA 6911",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 89.7,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 23.2,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 6911 denotes a complete needle roller bearing for a 55 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 80 mm OD and 45 mm width. The designation NA 6911 tells you the envelope — 55×80×45 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 55 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 45 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 89.7/190 kN ratings are SKF catalogue values for this exact execution (NA 6911); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 89.7/190 kN ratings and 780 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 6911 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6911 carries its own hardened, ground inner ring on a 55 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 6911 be mounted?",
        "a": "Mount the inner ring on the 55 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 6911?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 6911?",
        "a": "A NA 6911 measures 55 mm bore/Fw × 80 mm outside diameter × 45 mm width (2.165 × 3.15 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 89.7 kN, static C0 190 kN, fatigue limit Pu 23.2 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 780 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6911-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6911",
      "NA 6911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS55",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 55",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 85,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 66,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 14.6,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIS 55 provides the full machined-ring needle roller construction: ground inner ring on a 55 mm seat, flanged outer ring at 85 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 55 mm d and 28 mm B, the 85 mm outside diameter from the wide-section machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 6,000 r/min thermal reference and 6,700 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 55 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 28 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIS 55 shares its 55×85×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 66/114 kN ratings and 560 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 642); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKIS 55 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 55 mm bore, 28 mm width, 85 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKIS 55 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKIS 55 carries its own hardened, ground inner ring on a 55 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKIS 55?",
        "a": "Mount the inner ring on the 55 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKIS 55 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS55-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×85×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS55",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS55",
      "NKIS 55"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI60-25",
    "brand": "SKF",
    "manufacturer_designation": "NKI 60/25",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 82,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44,
    "static_load_kN": 95,
    "fatigue_load_limit_kN": 11.8,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 60/25 in the machined-ring needle roller bearings with inner ring with boundary dimensions 60×82×25 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NKI 60/25 tells you the envelope — 60×82×25 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 390 g at 60×82×25 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NKI 60/25 shares its 60×82×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 44/95 kN ratings and 390 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKI 60/25 be mounted?",
        "a": "Mount the inner ring on the 60 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 60/25?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 60 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 60/25?",
        "a": "A NKI 60/25 measures 60 mm bore/Fw × 82 mm outside diameter × 25 mm width (2.362 × 3.228 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44 kN, static C0 95 kN, fatigue limit Pu 11.8 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 390 g."
      },
      {
        "q": "How is the NKI 60/25 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 60 mm bore, 25 mm width, 82 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI60-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×82×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI60-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI60",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI60-25",
      "NKI 60/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI60-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 60/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 82,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 146,
    "fatigue_load_limit_kN": 18.3,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 60/35 measures 60×82×35 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 60 mm bore (d), 35 mm width; the 82 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 550 g at 60×82×35 mm makes this one of the highest capacity-per-gram choices in the machined-ring needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 60 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 35 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 60 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 60.5/146 kN ratings and 550 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 60/35 have?",
        "a": "A NKI 60/35 measures 60 mm bore/Fw × 82 mm outside diameter × 35 mm width (2.362 × 3.228 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 60.5 kN, static C0 146 kN, fatigue limit Pu 18.3 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 550 g."
      },
      {
        "q": "What does NKI 60/35 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 60 mm bore, 35 mm width, 82 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 60/35 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 60/35 carries its own hardened, ground inner ring on a 60 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 60/35?",
        "a": "Mount the inner ring on the 60 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI60-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI60-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×82×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI60",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI60-35",
      "NKI 60/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4912",
    "brand": "SKF",
    "manufacturer_designation": "NA 4912",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 14.3,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4912 in the dimension series 49 needle roller bearings with inner ring with boundary dimensions 60×85×25 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NA 4912 tells you the envelope — 60×85×25 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 430 g at 60×85×25 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 60 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 60.5/114 kN ratings and 430 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4912 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 60 mm bore, 25 mm width, 85 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4912 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4912 carries its own hardened, ground inner ring on a 60 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4912 be mounted?",
        "a": "Mount the inner ring on the 60 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4912?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 60 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4912-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×85×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4912",
      "NA 4912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6912",
    "brand": "SKF",
    "manufacturer_designation": "NA 6912",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 93.5,
    "static_load_kN": 204,
    "fatigue_load_limit_kN": 25,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 810,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 6912 provides the full machined-ring needle roller construction: ground inner ring on a 60 mm seat, flanged outer ring at 85 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 60 mm bore (d), 45 mm width; the 85 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 60 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 45 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 60 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 93.5/204 kN ratings and 810 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 6912 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 60 mm bore, 45 mm width, 85 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 6912 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6912 carries its own hardened, ground inner ring on a 60 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 6912?",
        "a": "Mount the inner ring on the 60 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 6912 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6912-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×85×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6912",
      "NA 6912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS60",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 60",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 90,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 68.2,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 15.3,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The wide-section machined-ring needle roller bearings with inner ring execution NKIS 60 measures 60×90×28 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 60 mm d and 28 mm B, the 90 mm outside diameter from the wide-section machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 5,600 r/min thermal reference and 6,300 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 60 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIS 60 shares its 60×90×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 68.2/120 kN ratings and 560 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKIS 60?",
        "a": "Mount the inner ring on the 60 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKIS 60 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKIS 60 have?",
        "a": "A NKIS 60 measures 60 mm bore/Fw × 90 mm outside diameter × 28 mm width (2.362 × 3.543 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 68.2 kN, static C0 120 kN, fatigue limit Pu 15.3 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 560 g."
      },
      {
        "q": "What does NKIS 60 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 60 mm bore, 28 mm width, 90 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS60-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 60×90×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS60",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS60",
      "NKIS 60"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI65-25",
    "brand": "SKF",
    "manufacturer_designation": "NKI 65/25",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 52.8,
    "static_load_kN": 106,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 65/25 measures 65×90×25 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 65 mm d and 25 mm B, the 90 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Speed planning separates the two ceilings: 5,600 r/min thermal reference and 6,300 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 65 mm seat. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 25 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 5,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 65 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 52.8/106 kN ratings and 460 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKI 65/25 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 65/25 carries its own hardened, ground inner ring on a 65 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 65/25?",
        "a": "Mount the inner ring on the 65 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 65/25 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 65/25 have?",
        "a": "A NKI 65/25 measures 65 mm bore/Fw × 90 mm outside diameter × 25 mm width (2.559 × 3.543 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 52.8 kN, static C0 106 kN, fatigue limit Pu 13.2 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 460 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI65-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×90×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI65-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NA4913",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×25 mm envelope, but catalogue C/C0 differ between the executions (52.8/106 vs 61.6/120 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI65-25",
      "NKI 65/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4913",
    "brand": "SKF",
    "manufacturer_designation": "NA 4913",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 61.6,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 14.6,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 65 mm shaft that cannot be hardened on site, NA 4913 adds a hardened, ground inner ring to the machined needle roller design: envelope 65×90×25 mm per the dimension series 49 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 65 mm bore (d), 25 mm width; the 90 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 460 g at 65×90×25 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 65 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 61.6/120 kN ratings are SKF catalogue values for this exact execution (NA 4913); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 61.6/120 kN ratings and 460 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 4913 have?",
        "a": "A NA 4913 measures 65 mm bore/Fw × 90 mm outside diameter × 25 mm width (2.559 × 3.543 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 61.6 kN, static C0 120 kN, fatigue limit Pu 14.6 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 460 g."
      },
      {
        "q": "What does NA 4913 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 65 mm bore, 25 mm width, 90 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4913 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4913 carries its own hardened, ground inner ring on a 65 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4913?",
        "a": "Mount the inner ring on the 65 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4913-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×90×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI65-25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×25 mm envelope, but catalogue C/C0 differ between the executions (61.6/120 vs 52.8/106 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4913",
      "NA 4913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI65-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 65/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 73.7,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 20.4,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 660,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 65/35 in the machined-ring needle roller bearings with inner ring with boundary dimensions 65×90×35 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NKI 65/35 tells you the envelope — 65×90×35 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Speed planning separates the two ceilings: 5,600 r/min thermal reference and 6,300 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 65 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 65 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 73.7/163 kN ratings are SKF catalogue values for this exact execution (NKI 65/35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 73.7/163 kN ratings and 660 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 65/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 65 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 65/35?",
        "a": "A NKI 65/35 measures 65 mm bore/Fw × 90 mm outside diameter × 35 mm width (2.559 × 3.543 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 73.7 kN, static C0 163 kN, fatigue limit Pu 20.4 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 660 g."
      },
      {
        "q": "How is the NKI 65/35 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 65 mm bore, 35 mm width, 90 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 65/35 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 65/35 carries its own hardened, ground inner ring on a 65 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI65-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI65-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×90×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI65",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI65-35",
      "NKI 65/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6913",
    "brand": "SKF",
    "manufacturer_designation": "NA 6913",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 95.2,
    "static_load_kN": 212,
    "fatigue_load_limit_kN": 26,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 6913 in the dimension series 69 needle roller bearings with inner ring with boundary dimensions 65×90×45 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NA 6913 code gives bore 65 mm and width 45 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 65 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 45 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 6913 shares its 65×90×45 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 95.2/212 kN ratings and 830 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 6913?",
        "a": "A NA 6913 measures 65 mm bore/Fw × 90 mm outside diameter × 45 mm width (2.559 × 3.543 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 95.2 kN, static C0 212 kN, fatigue limit Pu 26 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 830 g."
      },
      {
        "q": "How is the NA 6913 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 65 mm bore, 45 mm width, 90 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 6913 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6913 carries its own hardened, ground inner ring on a 65 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 6913 be mounted?",
        "a": "Mount the inner ring on the 65 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6913-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×90×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6913",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6913",
      "NA 6913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIS65",
    "brand": "SKF",
    "manufacturer_designation": "NKIS 65",
    "series": "NKIS-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 95,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 70.4,
    "static_load_kN": 132,
    "fatigue_load_limit_kN": 16.6,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 640,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIS 65 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 65 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NKIS 65 tells you the envelope — 65×95×28 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Speed planning separates the two ceilings: 5,300 r/min thermal reference and 6,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 65 mm seat. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NKIS 65 shares its 65×95×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 70.4/132 kN ratings and 640 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKIS 65 be mounted?",
        "a": "Mount the inner ring on the 65 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKIS 65?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 65 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIS 65?",
        "a": "A NKIS 65 measures 65 mm bore/Fw × 95 mm outside diameter × 28 mm width (2.559 × 3.74 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 70.4 kN, static C0 132 kN, fatigue limit Pu 16.6 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 640 g."
      },
      {
        "q": "How is the NKIS 65 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 65 mm bore, 28 mm width, 95 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS65-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 65×95×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKIS65",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIS65",
      "NKIS 65"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI70-25",
    "brand": "SKF",
    "manufacturer_designation": "NKI 70/25",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 95,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 56.1,
    "static_load_kN": 127,
    "fatigue_load_limit_kN": 15.6,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 510,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 70/25 denotes a complete needle roller bearing for a 70 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 95 mm OD and 25 mm width. The designation NKI 70/25 tells you the envelope — 70×95×25 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 510 g catalogue mass and 12.5 mm radial section ((95−70)/2) frame a rating of about 0.80 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 25 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 56.1/127 kN ratings and 510 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 70/25?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 70 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 70/25?",
        "a": "A NKI 70/25 measures 70 mm bore/Fw × 95 mm outside diameter × 25 mm width (2.756 × 3.74 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 56.1 kN, static C0 127 kN, fatigue limit Pu 15.6 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 510 g."
      },
      {
        "q": "How is the NKI 70/25 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 70 mm bore, 25 mm width, 95 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 70/25 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 70/25 carries its own hardened, ground inner ring on a 70 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI70-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×95×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI70-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI70",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI70-25",
      "NKI 70/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI70-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 70/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 95,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 24,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 70 mm shaft that cannot be hardened on site, NKI 70/35 adds a hardened, ground inner ring to the machined needle roller design: envelope 70×95×35 mm per the machined-ring needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 70 mm bore (d), 35 mm width; the 95 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 720 g catalogue mass and 12.5 mm radial section ((95−70)/2) frame a rating of about 1.09 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 70/35 shares its 70×95×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 76.5/190 kN ratings and 720 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKI 70/35 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 70 mm bore, 35 mm width, 95 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 70/35 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 70/35 carries its own hardened, ground inner ring on a 70 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 70/35?",
        "a": "Mount the inner ring on the 70 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 70/35 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI70-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI70-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×95×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI70",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI70-35",
      "NKI 70/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4914",
    "brand": "SKF",
    "manufacturer_designation": "NA 4914",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 100,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 84.2,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 20.8,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4914 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 70 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NA 4914 code gives bore 70 mm and width 30 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 730 g at 70×100×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 70 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 70 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 84.2/163 kN ratings are SKF catalogue values for this exact execution (NA 4914); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 84.2/163 kN ratings and 730 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 4914?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 70 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4914?",
        "a": "A NA 4914 measures 70 mm bore/Fw × 100 mm outside diameter × 30 mm width (2.756 × 3.937 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 84.2 kN, static C0 163 kN, fatigue limit Pu 20.8 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 730 g."
      },
      {
        "q": "How is the NA 4914 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 70 mm bore, 30 mm width, 100 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4914 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4914 carries its own hardened, ground inner ring on a 70 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4914-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×100×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4914",
      "NA 4914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6914",
    "brand": "SKF",
    "manufacturer_designation": "NA 6914",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 100,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 128,
    "static_load_kN": 285,
    "fatigue_load_limit_kN": 36,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 1350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 70 mm shaft that cannot be hardened on site, NA 6914 adds a hardened, ground inner ring to the machined needle roller design: envelope 70×100×54 mm per the dimension series 69 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 70 mm d and 54 mm B, the 100 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 70 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 54 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 6914 shares its 70×100×54 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 128/285 kN ratings and 1350 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 6914 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 6914 have?",
        "a": "A NA 6914 measures 70 mm bore/Fw × 100 mm outside diameter × 54 mm width (2.756 × 3.937 × 2.126 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 128 kN, static C0 285 kN, fatigue limit Pu 36 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 1350 g."
      },
      {
        "q": "What does NA 6914 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 70 mm bore, 54 mm width, 100 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 6914 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6914 carries its own hardened, ground inner ring on a 70 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6914-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 70×100×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6914",
      "NA 6914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI75-25",
    "brand": "SKF",
    "manufacturer_designation": "NKI 75/25",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 69.3,
    "static_load_kN": 132,
    "fatigue_load_limit_kN": 16.6,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 640,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 75 mm shaft that cannot be hardened on site, NKI 75/25 adds a hardened, ground inner ring to the machined needle roller design: envelope 75×105×25 mm per the machined-ring needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 75 mm d and 25 mm B, the 105 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 75 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKI 75/25 shares its 75×105×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 69.3/132 kN ratings and 640 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 75/25?",
        "a": "Mount the inner ring on the 75 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 75/25 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 75/25 have?",
        "a": "A NKI 75/25 measures 75 mm bore/Fw × 105 mm outside diameter × 25 mm width (2.953 × 4.134 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 69.3 kN, static C0 132 kN, fatigue limit Pu 16.6 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 640 g."
      },
      {
        "q": "What does NKI 75/25 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 75 mm bore, 25 mm width, 105 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI75-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×105×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI75-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI75",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI75-25",
      "NKI 75/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4915",
    "brand": "SKF",
    "manufacturer_designation": "NA 4915",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 84.2,
    "static_load_kN": 170,
    "fatigue_load_limit_kN": 21.6,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4915 measures 75×105×30 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 75 mm d and 30 mm B, the 105 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 780 g at 75×105×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 75 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 75 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 84.2/170 kN ratings and 780 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 4915?",
        "a": "Mount the inner ring on the 75 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4915 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4915 have?",
        "a": "A NA 4915 measures 75 mm bore/Fw × 105 mm outside diameter × 30 mm width (2.953 × 4.134 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 84.2 kN, static C0 170 kN, fatigue limit Pu 21.6 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 780 g."
      },
      {
        "q": "What does NA 4915 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 75 mm bore, 30 mm width, 105 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4915-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×105×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4915",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4915",
      "NA 4915"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI75-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 75/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 96.8,
    "static_load_kN": 200,
    "fatigue_load_limit_kN": 26,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 910,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 75/35 denotes a complete needle roller bearing for a 75 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 105 mm OD and 35 mm width. The designation NKI 75/35 tells you the envelope — 75×105×35 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 35 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NKI 75/35 shares its 75×105×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 96.8/200 kN ratings and 910 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 75/35?",
        "a": "A NKI 75/35 measures 75 mm bore/Fw × 105 mm outside diameter × 35 mm width (2.953 × 4.134 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 96.8 kN, static C0 200 kN, fatigue limit Pu 26 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 910 g."
      },
      {
        "q": "How is the NKI 75/35 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 75 mm bore, 35 mm width, 105 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 75/35 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 75/35 carries its own hardened, ground inner ring on a 75 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 75/35 be mounted?",
        "a": "Mount the inner ring on the 75 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI75-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI75-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×105×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI75",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI75-35",
      "NKI 75/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6915",
    "brand": "SKF",
    "manufacturer_designation": "NA 6915",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 130,
    "static_load_kN": 290,
    "fatigue_load_limit_kN": 37.5,
    "max_rpm": 5300,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 5300,
    "weight_g": 1450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 6915 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 75 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NA 6915 tells you the envelope — 75×105×54 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 75 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 54 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 75 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 130/290 kN ratings and 1450 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NA 6915 be mounted?",
        "a": "Mount the inner ring on the 75 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 6915?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 75 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 6915?",
        "a": "A NA 6915 measures 75 mm bore/Fw × 105 mm outside diameter × 54 mm width (2.953 × 4.134 × 2.126 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 130 kN, static C0 290 kN, fatigue limit Pu 37.5 kN, limiting speed 5,300 r/min, reference speed 4,800 r/min, mass about 1450 g."
      },
      {
        "q": "How is the NA 6915 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 75 mm bore, 54 mm width, 105 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6915-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 75×105×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6915",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6915",
      "NA 6915"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI80-25",
    "brand": "SKF",
    "manufacturer_designation": "NKI 80/25",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 110,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 72.1,
    "static_load_kN": 140,
    "fatigue_load_limit_kN": 18,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 680,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 80/25 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 80 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 80 mm d and 25 mm B, the 110 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Selection arithmetic: C 72.1 kN against C0 140 kN gives a C0/C ratio of 1.94, and the 18 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 80 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 25 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 72.1/140 kN ratings are SKF catalogue values for this exact execution (NKI 80/25); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 72.1/140 kN ratings and 680 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 80/25 have?",
        "a": "A NKI 80/25 measures 80 mm bore/Fw × 110 mm outside diameter × 25 mm width (3.15 × 4.331 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 72.1 kN, static C0 140 kN, fatigue limit Pu 18 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 680 g."
      },
      {
        "q": "What does NKI 80/25 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 80 mm bore, 25 mm width, 110 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 80/25 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 80/25 carries its own hardened, ground inner ring on a 80 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 80/25?",
        "a": "Mount the inner ring on the 80 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI80-25-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×110×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI80-35-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI80",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI80-25",
      "NKI 80/25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4916",
    "brand": "SKF",
    "manufacturer_designation": "NA 4916",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 110,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 88,
    "static_load_kN": 183,
    "fatigue_load_limit_kN": 23.2,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 880,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4916 denotes a complete needle roller bearing for a 80 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 110 mm OD and 30 mm width. The designation NA 4916 tells you the envelope — 80×110×30 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 880 g at 80×110×30 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 80 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 30 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 4916 shares its 80×110×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 4,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 88/183 kN ratings and 880 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 4916 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4916 carries its own hardened, ground inner ring on a 80 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4916 be mounted?",
        "a": "Mount the inner ring on the 80 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4916?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 80 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4916?",
        "a": "A NA 4916 measures 80 mm bore/Fw × 110 mm outside diameter × 30 mm width (3.15 × 4.331 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 88 kN, static C0 183 kN, fatigue limit Pu 23.2 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 880 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4916-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×110×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4916",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4916",
      "NA 4916"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI80-35",
    "brand": "SKF",
    "manufacturer_designation": "NKI 80/35",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 110,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 101,
    "static_load_kN": 216,
    "fatigue_load_limit_kN": 28,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 960,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKI 80/35 provides the full machined-ring needle roller construction: ground inner ring on a 80 mm seat, flanged outer ring at 110 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. The designation NKI 80/35 tells you the envelope — 80×110×35 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. The 2RS executions of the 49 series carry contact seals on both faces and a wider outer ring — their B and s dimensions differ from the open execution, so housings must be re-checked before substituting. Selection arithmetic: C 101 kN against C0 216 kN gives a C0/C ratio of 2.14, and the 28 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 35 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 101/216 kN ratings and 960 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKI 80/35 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 80/35 carries its own hardened, ground inner ring on a 80 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 80/35 be mounted?",
        "a": "Mount the inner ring on the 80 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 80/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 80 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 80/35?",
        "a": "A NKI 80/35 measures 80 mm bore/Fw × 110 mm outside diameter × 35 mm width (3.15 × 4.331 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 101 kN, static C0 216 kN, fatigue limit Pu 28 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 960 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI80-25-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI80-35-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×110×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI80",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI80-35",
      "NKI 80/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6916",
    "brand": "SKF",
    "manufacturer_designation": "NA 6916",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 80,
    "D_mm": 110,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 134,
    "static_load_kN": 315,
    "fatigue_load_limit_kN": 40,
    "max_rpm": 5000,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 5000,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 69 needle roller bearings with inner ring execution NA 6916 measures 80×110×54 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 80 mm bore (d), 54 mm width; the 110 mm OD follows the dimension series, and the inner ring is a separate ground component. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 80 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 54 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 80 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 134/315 kN ratings are SKF catalogue values for this exact execution (NA 6916); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 134/315 kN ratings and 1500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 6916 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6916 carries its own hardened, ground inner ring on a 80 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 6916?",
        "a": "Mount the inner ring on the 80 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 6916 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 6916 have?",
        "a": "A NA 6916 measures 80 mm bore/Fw × 110 mm outside diameter × 54 mm width (3.15 × 4.331 × 2.126 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 134 kN, static C0 315 kN, fatigue limit Pu 40 kN, limiting speed 5,000 r/min, reference speed 4,500 r/min, mass about 1500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6916-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 80×110×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6916",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6916",
      "NA 6916"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI85-26",
    "brand": "SKF",
    "manufacturer_designation": "NKI 85/26",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 115,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 73.7,
    "static_load_kN": 146,
    "fatigue_load_limit_kN": 18.6,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 740,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKI 85/26 in the machined-ring needle roller bearings with inner ring with boundary dimensions 85×115×26 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 85 mm d and 26 mm B, the 115 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. The 740 g catalogue mass and 15.0 mm radial section ((115−85)/2) frame a rating of about 0.87 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 73.7/146 kN ratings are SKF catalogue values for this exact execution (NKI 85/26); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 73.7/146 kN ratings and 740 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKI 85/26?",
        "a": "Mount the inner ring on the 85 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 85/26 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 85/26 have?",
        "a": "A NKI 85/26 measures 85 mm bore/Fw × 115 mm outside diameter × 26 mm width (3.346 × 4.528 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 73.7 kN, static C0 146 kN, fatigue limit Pu 18.6 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 740 g."
      },
      {
        "q": "What does NKI 85/26 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 85 mm bore, 26 mm width, 115 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI85-26-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×115×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI85-36-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI85",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI85-26",
      "NKI 85/26"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI85-36",
    "brand": "SKF",
    "manufacturer_designation": "NKI 85/36",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 115,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 105,
    "static_load_kN": 232,
    "fatigue_load_limit_kN": 30,
    "max_rpm": 4800,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 4800,
    "weight_g": 1050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The machined-ring needle roller bearings with inner ring execution NKI 85/36 measures 85×115×36 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. The designation NKI 85/36 tells you the envelope — 85×115×36 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. The 1050 g catalogue mass and 15.0 mm radial section ((115−85)/2) frame a rating of about 1.24 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: heat or press the inner ring onto the 85 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 36 mm assembly for free rotation before applying load.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 105/232 kN ratings and 1050 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 85/36?",
        "a": "A NKI 85/36 measures 85 mm bore/Fw × 115 mm outside diameter × 36 mm width (3.346 × 4.528 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 105 kN, static C0 232 kN, fatigue limit Pu 30 kN, limiting speed 4,800 r/min, reference speed 4,300 r/min, mass about 1050 g."
      },
      {
        "q": "How is the NKI 85/36 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 85 mm bore, 36 mm width, 115 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 85/36 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 85/36 carries its own hardened, ground inner ring on a 85 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 85/36 be mounted?",
        "a": "Mount the inner ring on the 85 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI85-26-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI85-36-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×115×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI85",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI85-36",
      "NKI 85/36"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4917",
    "brand": "SKF",
    "manufacturer_designation": "NA 4917",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 120,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 108,
    "static_load_kN": 250,
    "fatigue_load_limit_kN": 31,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 1250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4917 provides the full machined-ring needle roller construction: ground inner ring on a 85 mm seat, flanged outer ring at 120 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 85 mm bore (d), 35 mm width; the 120 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 1250 g at 85×120×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 85 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 35 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4917 shares its 85×120×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 108/250 kN ratings and 1250 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 4917 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 85 mm bore, 35 mm width, 120 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4917 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4917 carries its own hardened, ground inner ring on a 85 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4917?",
        "a": "Mount the inner ring on the 85 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4917 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4917-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×120×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4917",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4917",
      "NA 4917"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6917",
    "brand": "SKF",
    "manufacturer_designation": "NA 6917",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 85,
    "D_mm": 120,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 165,
    "static_load_kN": 425,
    "fatigue_load_limit_kN": 53,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 2200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 6917 denotes a complete needle roller bearing for a 85 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 120 mm OD and 63 mm width. The NA 6917 code gives bore 85 mm and width 63 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 85 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 63 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 85 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 85 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 165/425 kN ratings are SKF catalogue values for this exact execution (NA 6917); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 165/425 kN ratings and 2200 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 6917 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 85 mm bore, 63 mm width, 120 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 6917 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6917 carries its own hardened, ground inner ring on a 85 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 6917 be mounted?",
        "a": "Mount the inner ring on the 85 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 6917?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 85 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 17.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6917-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 85×120×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6917",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6917",
      "NA 6917"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI90-26",
    "brand": "SKF",
    "manufacturer_designation": "NKI 90/26",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 120,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 156,
    "fatigue_load_limit_kN": 19.6,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 90 mm shaft that cannot be hardened on site, NKI 90/26 adds a hardened, ground inner ring to the machined needle roller design: envelope 90×120×26 mm per the machined-ring needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 90 mm d and 26 mm B, the 120 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 4,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 90 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 76.5/156 kN ratings and 780 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKI 90/26 have?",
        "a": "A NKI 90/26 measures 90 mm bore/Fw × 120 mm outside diameter × 26 mm width (3.543 × 4.724 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 76.5 kN, static C0 156 kN, fatigue limit Pu 19.6 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 780 g."
      },
      {
        "q": "What does NKI 90/26 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 90 mm bore, 26 mm width, 120 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 90/26 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 90/26 carries its own hardened, ground inner ring on a 90 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 90/26?",
        "a": "Mount the inner ring on the 90 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI90-26-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×120×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI90-36-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI90",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI90-26",
      "NKI 90/26"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI90-36",
    "brand": "SKF",
    "manufacturer_designation": "NKI 90/36",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 120,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 108,
    "static_load_kN": 250,
    "fatigue_load_limit_kN": 31,
    "max_rpm": 4500,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 4500,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 90/36 denotes a complete needle roller bearing for a 90 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 120 mm OD and 36 mm width. The designation NKI 90/36 tells you the envelope — 90×120×36 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 90 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 36 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 90 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 108/250 kN ratings are SKF catalogue values for this exact execution (NKI 90/36); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 108/250 kN ratings and 1100 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKI 90/36 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 90/36 carries its own hardened, ground inner ring on a 90 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 90/36 be mounted?",
        "a": "Mount the inner ring on the 90 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NKI 90/36?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 90 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 90/36?",
        "a": "A NKI 90/36 measures 90 mm bore/Fw × 120 mm outside diameter × 36 mm width (3.543 × 4.724 × 1.417 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 108 kN, static C0 250 kN, fatigue limit Pu 31 kN, limiting speed 4,500 r/min, reference speed 4,000 r/min, mass about 1100 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI90-26-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI90-36-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×120×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI90",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI90-36",
      "NKI 90/36"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4918",
    "brand": "SKF",
    "manufacturer_designation": "NA 4918",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 125,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 112,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 32.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 1300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4918 in the dimension series 49 needle roller bearings with inner ring with boundary dimensions 90×125×35 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NA 4918 code gives bore 90 mm and width 35 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 1300 g at 90×125×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 90 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 35 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 112/265 kN ratings and 1300 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 4918?",
        "a": "A NA 4918 measures 90 mm bore/Fw × 125 mm outside diameter × 35 mm width (3.543 × 4.921 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 112 kN, static C0 265 kN, fatigue limit Pu 32.5 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 1300 g."
      },
      {
        "q": "How is the NA 4918 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 90 mm bore, 35 mm width, 125 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4918 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4918 carries its own hardened, ground inner ring on a 90 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4918 be mounted?",
        "a": "Mount the inner ring on the 90 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4918-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×125×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4918",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4918",
      "NA 4918"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6918",
    "brand": "SKF",
    "manufacturer_designation": "NA 6918",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 90,
    "D_mm": 125,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 172,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 55,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 2300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 6918 provides the full machined-ring needle roller construction: ground inner ring on a 90 mm seat, flanged outer ring at 125 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 90 mm d and 63 mm B, the 125 mm outside diameter from the dimension series 69 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 90 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 63 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 90 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 3,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 90 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 172/450 kN ratings and 2300 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 644); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 6918 have?",
        "a": "A NA 6918 measures 90 mm bore/Fw × 125 mm outside diameter × 63 mm width (3.543 × 4.921 × 2.48 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 172 kN, static C0 450 kN, fatigue limit Pu 55 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 2300 g."
      },
      {
        "q": "What does NA 6918 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 90 mm bore, 63 mm width, 125 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 6918 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 6918 carries its own hardened, ground inner ring on a 90 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 6918?",
        "a": "Mount the inner ring on the 90 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6918-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 90×125×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6918",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6918",
      "NA 6918"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI95-26",
    "brand": "SKF",
    "manufacturer_designation": "NKI 95/26",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 95,
    "D_mm": 125,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 78.1,
    "static_load_kN": 166,
    "fatigue_load_limit_kN": 20.4,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 95/26 denotes a complete needle roller bearing for a 95 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 125 mm OD and 26 mm width. The NKI 95/26 code gives bore 95 mm and width 26 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 78.1 kN against C0 166 kN gives a C0/C ratio of 2.13, and the 20.4 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 26 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 95 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 95 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 78.1/166 kN ratings are SKF catalogue values for this exact execution (NKI 95/26); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 78.1/166 kN ratings and 820 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKI 95/26?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 95 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKI 95/26?",
        "a": "A NKI 95/26 measures 95 mm bore/Fw × 125 mm outside diameter × 26 mm width (3.74 × 4.921 × 1.024 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 78.1 kN, static C0 166 kN, fatigue limit Pu 20.4 kN, limiting speed 4,300 r/min, reference speed 3,800 r/min, mass about 820 g."
      },
      {
        "q": "How is the NKI 95/26 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 95 mm bore, 26 mm width, 125 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 95/26 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 95/26 carries its own hardened, ground inner ring on a 95 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI95-26-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 95×125×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI95-36-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI95",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI95-26",
      "NKI 95/26"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI95-36",
    "brand": "SKF",
    "manufacturer_designation": "NKI 95/36",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 95,
    "D_mm": 125,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 112,
    "static_load_kN": 265,
    "fatigue_load_limit_kN": 32.5,
    "max_rpm": 4300,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 4300,
    "weight_g": 1150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 95 mm shaft that cannot be hardened on site, NKI 95/36 adds a hardened, ground inner ring to the machined needle roller design: envelope 95×125×36 mm per the machined-ring needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 95 mm d and 36 mm B, the 125 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 112 kN against C0 265 kN gives a C0/C ratio of 2.37, and the 32.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 95 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 112/265 kN ratings are SKF catalogue values for this exact execution (NKI 95/36); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 112/265 kN ratings and 1150 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKI 95/36 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 95 mm bore, 36 mm width, 125 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NKI 95/36 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 95/36 carries its own hardened, ground inner ring on a 95 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 95/36?",
        "a": "Mount the inner ring on the 95 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 95/36 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI95-26-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI95-36-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 95×125×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI95",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI95-36",
      "NKI 95/36"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4919",
    "brand": "SKF",
    "manufacturer_designation": "NA 4919",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 95,
    "D_mm": 130,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 114,
    "static_load_kN": 270,
    "fatigue_load_limit_kN": 33.5,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 1350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 95 mm shaft that cannot be hardened on site, NA 4919 adds a hardened, ground inner ring to the machined needle roller design: envelope 95×130×35 mm per the dimension series 49 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 95 mm d and 35 mm B, the 130 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 1350 g at 95×130×35 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: heat or press the inner ring onto the 95 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 35 mm assembly for free rotation before applying load.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 95 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 114/270 kN ratings are SKF catalogue values for this exact execution (NA 4919); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 114/270 kN ratings and 1350 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4919 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4919 have?",
        "a": "A NA 4919 measures 95 mm bore/Fw × 130 mm outside diameter × 35 mm width (3.74 × 5.118 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 114 kN, static C0 270 kN, fatigue limit Pu 33.5 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 1350 g."
      },
      {
        "q": "What does NA 4919 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 95 mm bore, 35 mm width, 130 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4919 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4919 carries its own hardened, ground inner ring on a 95 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4919-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 95×130×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4919",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4919",
      "NA 4919"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA6919",
    "brand": "SKF",
    "manufacturer_designation": "NA 6919",
    "series": "NA-69-series",
    "type": "needle",
    "d_mm": 95,
    "D_mm": 130,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 172,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 56,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 2500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 6919 in the dimension series 69 needle roller bearings with inner ring with boundary dimensions 95×130×63 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NA 6919 tells you the envelope — 95×130×63 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Inner rings are separable: order replacement inner rings separately by d×D×B, since the outer ring and roller assembly survive journals that ruin an inner raceway. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. Mounting: heat or press the inner ring onto the 95 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 63 mm assembly for free rotation before applying load.",
    "applications": [
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 95 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 6919 shares its 95×130×63 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 172/465 kN ratings and 2500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 6919?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 95 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 17.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 6919?",
        "a": "A NA 6919 measures 95 mm bore/Fw × 130 mm outside diameter × 63 mm width (3.74 × 5.118 × 2.48 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 172 kN, static C0 465 kN, fatigue limit Pu 56 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 2500 g."
      },
      {
        "q": "How is the NA 6919 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 95 mm bore, 63 mm width, 130 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 6919 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 6919 carries its own hardened, ground inner ring on a 95 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA6919-ZW-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 95×130×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA6919",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA6919",
      "NA 6919"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI100-30",
    "brand": "SKF",
    "manufacturer_designation": "NKI 100/30",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 130,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 96.8,
    "static_load_kN": 220,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKI 100/30 denotes a complete needle roller bearing for a 100 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 130 mm OD and 30 mm width. The NKI 100/30 code gives bore 100 mm and width 30 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 990 g catalogue mass and 15.0 mm radial section ((130−100)/2) frame a rating of about 0.97 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 100 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 96.8/220 kN ratings are SKF catalogue values for this exact execution (NKI 100/30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 96.8/220 kN ratings and 990 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKI 100/30?",
        "a": "A NKI 100/30 measures 100 mm bore/Fw × 130 mm outside diameter × 30 mm width (3.937 × 5.118 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 96.8 kN, static C0 220 kN, fatigue limit Pu 27 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 990 g."
      },
      {
        "q": "How is the NKI 100/30 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 100 mm bore, 30 mm width, 130 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NKI 100/30 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NKI 100/30 carries its own hardened, ground inner ring on a 100 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NKI 100/30 be mounted?",
        "a": "Mount the inner ring on the 100 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI100-30-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×130×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI100-40-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI100",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI100-30",
      "NKI 100/30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKI100-40",
    "brand": "SKF",
    "manufacturer_designation": "NKI 100/40",
    "series": "NKI-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 130,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 123,
    "static_load_kN": 305,
    "fatigue_load_limit_kN": 37.5,
    "max_rpm": 4000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4000,
    "weight_g": 1350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 100 mm shaft that cannot be hardened on site, NKI 100/40 adds a hardened, ground inner ring to the machined needle roller design: envelope 100×130×40 mm per the machined-ring needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 100 mm d and 40 mm B, the 130 mm outside diameter from the machined-ring needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. The 1350 g catalogue mass and 15.0 mm radial section ((130−100)/2) frame a rating of about 1.23 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: heat or press the inner ring onto the 100 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 40 mm assembly for free rotation before applying load.",
    "applications": [
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads",
      "electric motor armature shafts with ground seats",
      "printing and paper-handling rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 123/305 kN ratings are SKF catalogue values for this exact execution (NKI 100/40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 123/305 kN ratings and 1350 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKI 100/40 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NKI 100/40 carries its own hardened, ground inner ring on a 100 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NKI 100/40?",
        "a": "Mount the inner ring on the 100 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NKI 100/40 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NKI 100/40 have?",
        "a": "A NKI 100/40 measures 100 mm bore/Fw × 130 mm outside diameter × 40 mm width (3.937 × 5.118 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 123 kN, static C0 305 kN, fatigue limit Pu 37.5 kN, limiting speed 4,000 r/min, reference speed 3,600 r/min, mass about 1350 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI100-30-XL",
        "equiv_brand": "FAG",
        "level": "verify",
        "note": "Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue."
      },
      {
        "equiv_sku": "NKI100-40-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×130×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NKI100",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKI100-40",
      "NKI 100/40"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4920",
    "brand": "SKF",
    "manufacturer_designation": "NA 4920",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 100,
    "D_mm": 140,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 125,
    "static_load_kN": 280,
    "fatigue_load_limit_kN": 34,
    "max_rpm": 4000,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 4000,
    "weight_g": 1900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 100 mm shaft that cannot be hardened on site, NA 4920 adds a hardened, ground inner ring to the machined needle roller design: envelope 100×140×40 mm per the dimension series 49 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 100 mm d and 40 mm B, the 140 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 1900 g at 100×140×40 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 40 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 100 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 3,400 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 100 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 125/280 kN ratings and 1900 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 4920 have?",
        "a": "A NA 4920 measures 100 mm bore/Fw × 140 mm outside diameter × 40 mm width (3.937 × 5.512 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 125 kN, static C0 280 kN, fatigue limit Pu 34 kN, limiting speed 4,000 r/min, reference speed 3,400 r/min, mass about 1900 g."
      },
      {
        "q": "What does NA 4920 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 100 mm bore, 40 mm width, 140 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4920 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4920 carries its own hardened, ground inner ring on a 100 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4920?",
        "a": "Mount the inner ring on the 100 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4920-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 100×140×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4920",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4920",
      "NA 4920"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4822",
    "brand": "SKF",
    "manufacturer_designation": "NA 4822",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 110,
    "D_mm": 140,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 93.5,
    "static_load_kN": 232,
    "fatigue_load_limit_kN": 27,
    "max_rpm": 3800,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 3800,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4822 in the dimension series 48 needle roller bearings with inner ring with boundary dimensions 110×140×30 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NA 4822 tells you the envelope — 110×140×30 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 93.5 kN against C0 232 kN gives a C0/C ratio of 2.48, and the 27 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 30 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 110 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 4822 shares its 110×140×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 3,400 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 93.5/232 kN ratings and 1100 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NA 4822 be mounted?",
        "a": "Mount the inner ring on the 110 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4822?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 110 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4822?",
        "a": "A NA 4822 measures 110 mm bore/Fw × 140 mm outside diameter × 30 mm width (4.331 × 5.512 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 93.5 kN, static C0 232 kN, fatigue limit Pu 27 kN, limiting speed 3,800 r/min, reference speed 3,400 r/min, mass about 1100 g."
      },
      {
        "q": "How is the NA 4822 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 110 mm bore, 30 mm width, 140 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4822-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 110×140×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4822",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4822",
      "NA 4822"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4922",
    "brand": "SKF",
    "manufacturer_designation": "NA 4922",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 110,
    "D_mm": 150,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 130,
    "static_load_kN": 300,
    "fatigue_load_limit_kN": 35.5,
    "max_rpm": 3600,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3600,
    "weight_g": 2050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4922 measures 110×150×40 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 110 mm bore (d), 40 mm width; the 150 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 2050 g at 110×150×40 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 40 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 110 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4922 shares its 110×150×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 130/300 kN ratings and 2050 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 4922?",
        "a": "Mount the inner ring on the 110 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4922 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4922 have?",
        "a": "A NA 4922 measures 110 mm bore/Fw × 150 mm outside diameter × 40 mm width (4.331 × 5.906 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 130 kN, static C0 300 kN, fatigue limit Pu 35.5 kN, limiting speed 3,600 r/min, reference speed 3,200 r/min, mass about 2050 g."
      },
      {
        "q": "What does NA 4922 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 110 mm bore, 40 mm width, 150 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4922-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 110×150×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4922",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4922",
      "NA 4922"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4824",
    "brand": "SKF",
    "manufacturer_designation": "NA 4824",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 120,
    "D_mm": 150,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 99,
    "static_load_kN": 255,
    "fatigue_load_limit_kN": 29,
    "max_rpm": 3600,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 3600,
    "weight_g": 1150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4824 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 120 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NA 4824 code gives bore 120 mm and width 30 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 99 kN against C0 255 kN gives a C0/C ratio of 2.58, and the 29 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 30 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 120 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 99/255 kN ratings and 1150 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4824 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 120 mm bore, 30 mm width, 150 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4824 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4824 carries its own hardened, ground inner ring on a 120 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4824 be mounted?",
        "a": "Mount the inner ring on the 120 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4824?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 120 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4824-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 120×150×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4824",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4824",
      "NA 4824"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4924",
    "brand": "SKF",
    "manufacturer_designation": "NA 4924",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 120,
    "D_mm": 165,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 176,
    "static_load_kN": 405,
    "fatigue_load_limit_kN": 49,
    "max_rpm": 3400,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 3400,
    "weight_g": 2850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4924 provides the full machined-ring needle roller construction: ground inner ring on a 120 mm seat, flanged outer ring at 165 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 120 mm d and 45 mm B, the 165 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 2850 g at 120×165×45 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 45 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 120 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 176/405 kN ratings are SKF catalogue values for this exact execution (NA 4924); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 176/405 kN ratings and 2850 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 4924 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 120 mm bore, 45 mm width, 165 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4924 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4924 carries its own hardened, ground inner ring on a 120 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4924?",
        "a": "Mount the inner ring on the 120 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4924 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4924-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 120×165×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4924",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4924",
      "NA 4924"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4826",
    "brand": "SKF",
    "manufacturer_designation": "NA 4826",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 130,
    "D_mm": 165,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 119,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 36.5,
    "max_rpm": 3200,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3200,
    "weight_g": 1800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4826 denotes a complete needle roller bearing for a 130 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 165 mm OD and 35 mm width. The designation NA 4826 tells you the envelope — 130×165×35 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 119 kN against C0 325 kN gives a C0/C ratio of 2.73, and the 36.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 35 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 130 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 130 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 119/325 kN ratings are SKF catalogue values for this exact execution (NA 4826); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 119/325 kN ratings and 1800 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 4826?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 130 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 17.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4826?",
        "a": "A NA 4826 measures 130 mm bore/Fw × 165 mm outside diameter × 35 mm width (5.118 × 6.496 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 119 kN, static C0 325 kN, fatigue limit Pu 36.5 kN, limiting speed 3,200 r/min, reference speed 2,800 r/min, mass about 1800 g."
      },
      {
        "q": "How is the NA 4826 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 130 mm bore, 35 mm width, 165 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4826 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4826 carries its own hardened, ground inner ring on a 130 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4826-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 130×165×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4826",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4826",
      "NA 4826"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4926",
    "brand": "SKF",
    "manufacturer_designation": "NA 4926",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 130,
    "D_mm": 180,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 198,
    "static_load_kN": 480,
    "fatigue_load_limit_kN": 57,
    "max_rpm": 3000,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3000,
    "weight_g": 3900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 130 mm shaft that cannot be hardened on site, NA 4926 adds a hardened, ground inner ring to the machined needle roller design: envelope 130×180×50 mm per the dimension series 49 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 130 mm bore (d), 50 mm width; the 180 mm OD follows the dimension series, and the inner ring is a separate ground component. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 3900 g at 130×180×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 50 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 130 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 2,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 130 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 198/480 kN ratings and 3900 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4926 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4926 have?",
        "a": "A NA 4926 measures 130 mm bore/Fw × 180 mm outside diameter × 50 mm width (5.118 × 7.087 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 198 kN, static C0 480 kN, fatigue limit Pu 57 kN, limiting speed 3,000 r/min, reference speed 2,600 r/min, mass about 3900 g."
      },
      {
        "q": "What does NA 4926 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 130 mm bore, 50 mm width, 180 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4926 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4926 carries its own hardened, ground inner ring on a 130 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4926-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 130×180×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4926",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4926",
      "NA 4926"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4828",
    "brand": "SKF",
    "manufacturer_designation": "NA 4828",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 140,
    "D_mm": 175,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 121,
    "static_load_kN": 345,
    "fatigue_load_limit_kN": 37.5,
    "max_rpm": 3000,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3000,
    "weight_g": 1900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4828 in the dimension series 48 needle roller bearings with inner ring with boundary dimensions 140×175×35 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NA 4828 code gives bore 140 mm and width 35 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 121 kN against C0 345 kN gives a C0/C ratio of 2.85, and the 37.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 35 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 140 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 4828 shares its 140×175×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 2,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 121/345 kN ratings and 1900 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NA 4828 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4828 carries its own hardened, ground inner ring on a 140 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4828 be mounted?",
        "a": "Mount the inner ring on the 140 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4828?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 140 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 17.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4828?",
        "a": "A NA 4828 measures 140 mm bore/Fw × 175 mm outside diameter × 35 mm width (5.512 × 6.89 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 121 kN, static C0 345 kN, fatigue limit Pu 37.5 kN, limiting speed 3,000 r/min, reference speed 2,600 r/min, mass about 1900 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4828-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 140×175×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4828",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4828",
      "NA 4828"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4928",
    "brand": "SKF",
    "manufacturer_designation": "NA 4928",
    "series": "NA-49-series",
    "type": "needle",
    "d_mm": 140,
    "D_mm": 190,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 205,
    "static_load_kN": 510,
    "fatigue_load_limit_kN": 60,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 4150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 49 needle roller bearings with inner ring execution NA 4928 measures 140×190×50 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 140 mm d and 50 mm B, the 190 mm outside diameter from the dimension series 49 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. TN polymer cage executions run quieter and tolerate grease-lubricated pivot duty; steel cage executions remain the choice for higher temperature or oil-bath lubrication. Catalogue mass 4150 g at 140×190×50 mm makes this one of the highest capacity-per-gram choices in the dimension series 49 needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 50 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "printing and paper-handling rollers",
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 140 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4928 shares its 140×190×50 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 205/510 kN ratings and 4150 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 4928 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4928 carries its own hardened, ground inner ring on a 140 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4928?",
        "a": "Mount the inner ring on the 140 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4928 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4928 have?",
        "a": "A NA 4928 measures 140 mm bore/Fw × 190 mm outside diameter × 50 mm width (5.512 × 7.48 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 205 kN, static C0 510 kN, fatigue limit Pu 60 kN, limiting speed 2,800 r/min, reference speed 2,400 r/min, mass about 4150 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4928-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 140×190×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4928",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4928",
      "NA 4928"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4830",
    "brand": "SKF",
    "manufacturer_designation": "NA 4830",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 150,
    "D_mm": 190,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 147,
    "static_load_kN": 415,
    "fatigue_load_limit_kN": 46.5,
    "max_rpm": 2800,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 2800,
    "weight_g": 2700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 150 mm shaft that cannot be hardened on site, NA 4830 adds a hardened, ground inner ring to the machined needle roller design: envelope 150×190×40 mm per the dimension series 48 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 150 mm d and 40 mm B, the 190 mm outside diameter from the dimension series 48 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 147 kN against C0 415 kN gives a C0/C ratio of 2.82, and the 46.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 150 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 147/415 kN ratings are SKF catalogue values for this exact execution (NA 4830); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 147/415 kN ratings and 2700 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NA 4830 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4830 carries its own hardened, ground inner ring on a 150 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4830?",
        "a": "Mount the inner ring on the 150 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4830 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4830 have?",
        "a": "A NA 4830 measures 150 mm bore/Fw × 190 mm outside diameter × 40 mm width (5.906 × 7.48 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 147 kN, static C0 415 kN, fatigue limit Pu 46.5 kN, limiting speed 2,800 r/min, reference speed 2,400 r/min, mass about 2700 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4830-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 150×190×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4830",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4830",
      "NA 4830"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4832",
    "brand": "SKF",
    "manufacturer_designation": "NA 4832",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 160,
    "D_mm": 200,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 157,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 49,
    "max_rpm": 2600,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2600,
    "weight_g": 2850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 48 needle roller bearings with inner ring execution NA 4832 measures 160×200×40 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 160 mm bore (d), 40 mm width; the 200 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 157 kN against C0 450 kN gives a C0/C ratio of 2.87, and the 49 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 160 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 2,200 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 160 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 157/450 kN ratings and 2850 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 4832 have?",
        "a": "A NA 4832 measures 160 mm bore/Fw × 200 mm outside diameter × 40 mm width (6.299 × 7.874 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 157 kN, static C0 450 kN, fatigue limit Pu 49 kN, limiting speed 2,600 r/min, reference speed 2,200 r/min, mass about 2850 g."
      },
      {
        "q": "What does NA 4832 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 160 mm bore, 40 mm width, 200 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4832 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4832 carries its own hardened, ground inner ring on a 160 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4832?",
        "a": "Mount the inner ring on the 160 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4832-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 160×200×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4832",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4832",
      "NA 4832"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4834",
    "brand": "SKF",
    "manufacturer_designation": "NA 4834",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 170,
    "D_mm": 215,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 179,
    "static_load_kN": 520,
    "fatigue_load_limit_kN": 56,
    "max_rpm": 2400,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2400,
    "weight_g": 3950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4834 provides the full machined-ring needle roller construction: ground inner ring on a 170 mm seat, flanged outer ring at 215 mm, caged needles between them — the standard choice when a replaceable inner raceway is required. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 170 mm d and 45 mm B, the 215 mm outside diameter from the dimension series 48 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 179 kN against C0 520 kN gives a C0/C ratio of 2.91, and the 56 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 170 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4834 shares its 170×215×45 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 179/520 kN ratings and 3950 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 4834?",
        "a": "Mount the inner ring on the 170 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4834 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4834 have?",
        "a": "A NA 4834 measures 170 mm bore/Fw × 215 mm outside diameter × 45 mm width (6.693 × 8.465 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 179 kN, static C0 520 kN, fatigue limit Pu 56 kN, limiting speed 2,400 r/min, reference speed 2,200 r/min, mass about 3950 g."
      },
      {
        "q": "What does NA 4834 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 170 mm bore, 45 mm width, 215 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4834-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 170×215×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4834",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4834",
      "NA 4834"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4836",
    "brand": "SKF",
    "manufacturer_designation": "NA 4836",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 180,
    "D_mm": 225,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 190,
    "static_load_kN": 570,
    "fatigue_load_limit_kN": 60,
    "max_rpm": 2400,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2400,
    "weight_g": 4200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 180 mm shaft that cannot be hardened on site, NA 4836 adds a hardened, ground inner ring to the machined needle roller design: envelope 180×225×45 mm per the dimension series 48 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 180 mm bore (d), 45 mm width; the 225 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 190 kN against C0 570 kN gives a C0/C ratio of 3.00, and the 60 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 180 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 190/570 kN ratings are SKF catalogue values for this exact execution (NA 4836); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 190/570 kN ratings and 4200 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NA 4836 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 180 mm bore, 45 mm width, 225 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4836 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4836 carries its own hardened, ground inner ring on a 180 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4836?",
        "a": "Mount the inner ring on the 180 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4836 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4836-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 180×225×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4836",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4836",
      "NA 4836"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4838",
    "brand": "SKF",
    "manufacturer_designation": "NA 4838",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 190,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 220,
    "static_load_kN": 710,
    "fatigue_load_limit_kN": 73.5,
    "max_rpm": 2200,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2200,
    "weight_g": 5550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 48 needle roller bearings with inner ring execution NA 4838 measures 190×240×50 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 190 mm d and 50 mm B, the 240 mm outside diameter from the dimension series 48 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 220 kN against C0 710 kN gives a C0/C ratio of 3.23, and the 73.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 190 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 1,900 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 190 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 220/710 kN ratings and 5550 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4838 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4838 have?",
        "a": "A NA 4838 measures 190 mm bore/Fw × 240 mm outside diameter × 50 mm width (7.48 × 9.449 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 220 kN, static C0 710 kN, fatigue limit Pu 73.5 kN, limiting speed 2,200 r/min, reference speed 1,900 r/min, mass about 5550 g."
      },
      {
        "q": "What does NA 4838 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 190 mm bore, 50 mm width, 240 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4838 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4838 carries its own hardened, ground inner ring on a 190 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4838-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 190×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4838",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4838",
      "NA 4838"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4840",
    "brand": "SKF",
    "manufacturer_designation": "NA 4840",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 200,
    "D_mm": 250,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 224,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 75,
    "max_rpm": 2000,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 2000,
    "weight_g": 5800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4840 denotes a complete needle roller bearing for a 200 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 250 mm OD and 50 mm width. The designation NA 4840 tells you the envelope — 200×250×50 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 224 kN against C0 735 kN gives a C0/C ratio of 3.28, and the 75 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 200 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 50 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 200 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 224/735 kN ratings and 5800 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 4840?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 200 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 25.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4840?",
        "a": "A NA 4840 measures 200 mm bore/Fw × 250 mm outside diameter × 50 mm width (7.874 × 9.843 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 224 kN, static C0 735 kN, fatigue limit Pu 75 kN, limiting speed 2,000 r/min, reference speed 1,800 r/min, mass about 5800 g."
      },
      {
        "q": "How is the NA 4840 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 200 mm bore, 50 mm width, 250 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4840 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4840 carries its own hardened, ground inner ring on a 200 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4840-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 200×250×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4840",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4840",
      "NA 4840"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4844",
    "brand": "SKF",
    "manufacturer_designation": "NA 4844",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 220,
    "D_mm": 270,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 238,
    "static_load_kN": 815,
    "fatigue_load_limit_kN": 81.5,
    "max_rpm": 1900,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 1900,
    "weight_g": 6350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4844 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 220 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The designation NA 4844 tells you the envelope — 220×270×50 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 238 kN against C0 815 kN gives a C0/C ratio of 3.42, and the 81.5 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 220 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 50 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 220 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 4844 shares its 220×270×50 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 1,700 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 238/815 kN ratings and 6350 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 4844?",
        "a": "A NA 4844 measures 220 mm bore/Fw × 270 mm outside diameter × 50 mm width (8.661 × 10.63 × 1.969 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 238 kN, static C0 815 kN, fatigue limit Pu 81.5 kN, limiting speed 1,900 r/min, reference speed 1,700 r/min, mass about 6350 g."
      },
      {
        "q": "How is the NA 4844 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 220 mm bore, 50 mm width, 270 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4844 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4844 carries its own hardened, ground inner ring on a 220 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4844 be mounted?",
        "a": "Mount the inner ring on the 220 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4844-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 220×270×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4844",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4844",
      "NA 4844"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4848",
    "brand": "SKF",
    "manufacturer_designation": "NA 4848",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 240,
    "D_mm": 300,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 347,
    "static_load_kN": 1120,
    "fatigue_load_limit_kN": 112,
    "max_rpm": 1700,
    "reference_speed_rpm": 1500,
    "limiting_speed_rpm": 1700,
    "weight_g": 9900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4848 in the dimension series 48 needle roller bearings with inner ring with boundary dimensions 240×300×60 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The designation NA 4848 tells you the envelope — 240×300×60 mm — and the family tells you the construction: complete bearing, replaceable inner ring, flanged outer ring retaining the needle rollers. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 347 kN against C0 1120 kN gives a C0/C ratio of 3.23, and the 112 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 240 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 60 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 240 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 240 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 347/1120 kN ratings are SKF catalogue values for this exact execution (NA 4848); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 347/1120 kN ratings and 9900 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NA 4848 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 240 mm bore, 60 mm width, 300 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4848 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4848 carries its own hardened, ground inner ring on a 240 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4848 be mounted?",
        "a": "Mount the inner ring on the 240 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4848?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 240 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 30.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4848-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 240×300×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4848",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4848",
      "NA 4848"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4852",
    "brand": "SKF",
    "manufacturer_designation": "NA 4852",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 260,
    "D_mm": 320,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 358,
    "static_load_kN": 1200,
    "fatigue_load_limit_kN": 118,
    "max_rpm": 1500,
    "reference_speed_rpm": 1400,
    "limiting_speed_rpm": 1500,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 48 needle roller bearings with inner ring execution NA 4852 measures 260×320×60 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 260 mm d and 60 mm B, the 320 mm outside diameter from the dimension series 48 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 358 kN against C0 1200 kN gives a C0/C ratio of 3.35, and the 118 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 60 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 260 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 358/1200 kN ratings are SKF catalogue values for this exact execution (NA 4852); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 358/1200 kN ratings and 10500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4852 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4852 have?",
        "a": "A NA 4852 measures 260 mm bore/Fw × 320 mm outside diameter × 60 mm width (10.236 × 12.598 × 2.362 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 358 kN, static C0 1200 kN, fatigue limit Pu 118 kN, limiting speed 1,500 r/min, reference speed 1,400 r/min, mass about 10500 g."
      },
      {
        "q": "What does NA 4852 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 260 mm bore, 60 mm width, 320 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4852 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4852 carries its own hardened, ground inner ring on a 260 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4852-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 260×320×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4852",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4852",
      "NA 4852"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4856",
    "brand": "SKF",
    "manufacturer_designation": "NA 4856",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 280,
    "D_mm": 350,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 429,
    "static_load_kN": 1320,
    "fatigue_load_limit_kN": 129,
    "max_rpm": 1400,
    "reference_speed_rpm": 1300,
    "limiting_speed_rpm": 1400,
    "weight_g": 15500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 280 mm shaft that cannot be hardened on site, NA 4856 adds a hardened, ground inner ring to the machined needle roller design: envelope 280×350×69 mm per the dimension series 48 needle roller bearings with inner ring plan. In SKF nomenclature the leading letters mark a machined-ring needle bearing with inner ring: figures state 280 mm d and 69 mm B, the 350 mm outside diameter from the dimension series 48 needle roller bearings with inner ring, and the 2RS suffix would add contact seals. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 429 kN against C0 1320 kN gives a C0/C ratio of 3.08, and the 129 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. For NA 49 2RS executions the wider outer ring changes the housing depth: verify the 69 mm width and s offset dimensions against the open execution before reusing an existing bore.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 280 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4856 shares its 280×350×69 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 429/1320 kN ratings and 15500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NA 4856 have?",
        "a": "A NA 4856 measures 280 mm bore/Fw × 350 mm outside diameter × 69 mm width (11.024 × 13.78 × 2.717 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 429 kN, static C0 1320 kN, fatigue limit Pu 129 kN, limiting speed 1,400 r/min, reference speed 1,300 r/min, mass about 15500 g."
      },
      {
        "q": "What does NA 4856 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 280 mm bore, 69 mm width, 350 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4856 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4856 carries its own hardened, ground inner ring on a 280 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "What mounting mistakes ruin a NA 4856?",
        "a": "Mount the inner ring on the 280 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4856-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 280×350×69 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4856",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4856",
      "NA 4856"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4860",
    "brand": "SKF",
    "manufacturer_designation": "NA 4860",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 300,
    "D_mm": 380,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 594,
    "static_load_kN": 1800,
    "fatigue_load_limit_kN": 173,
    "max_rpm": 1300,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1300,
    "weight_g": 22000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NA 4860 denotes a complete needle roller bearing for a 300 mm shaft — machined inner and outer rings, integral flanges on the outer ring retaining the roller set, 380 mm OD and 80 mm width. The NA 4860 code gives bore 300 mm and width 80 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 594 kN against C0 1800 kN gives a C0/C ratio of 3.03, and the 173 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 300 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NA 4860 shares its 300×380×80 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 1,100 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 594/1800 kN ratings and 22000 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NA 4860 be mounted?",
        "a": "Mount the inner ring on the 300 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "What limits the service life of a NA 4860?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 300 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 40.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4860?",
        "a": "A NA 4860 measures 300 mm bore/Fw × 380 mm outside diameter × 80 mm width (11.811 × 14.961 × 3.15 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 594 kN, static C0 1800 kN, fatigue limit Pu 173 kN, limiting speed 1,300 r/min, reference speed 1,100 r/min, mass about 22000 g."
      },
      {
        "q": "How is the NA 4860 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 300 mm bore, 80 mm width, 380 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4860-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 300×380×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4860",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4860",
      "NA 4860"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4864",
    "brand": "SKF",
    "manufacturer_designation": "NA 4864",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 320,
    "D_mm": 400,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 605,
    "static_load_kN": 1900,
    "fatigue_load_limit_kN": 176,
    "max_rpm": 1200,
    "reference_speed_rpm": 1100,
    "limiting_speed_rpm": 1200,
    "weight_g": 23000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "NA 4864 is a machined-ring needle roller bearing with an inner ring: flanged outer ring plus a separate 320 mm bore inner ring, so the shaft seat needs only ordinary tolerance, as tabulated by SKF in SKF catalogue PUB BU/P1 17000. The NA 4864 code gives bore 320 mm and width 80 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 605 kN against C0 1900 kN gives a C0/C ratio of 3.14, and the 176 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 320 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 320 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 605/1900 kN ratings are SKF catalogue values for this exact execution (NA 4864); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 605/1900 kN ratings and 23000 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 646); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NA 4864?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 320 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 40.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NA 4864?",
        "a": "A NA 4864 measures 320 mm bore/Fw × 400 mm outside diameter × 80 mm width (12.598 × 15.748 × 3.15 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 605 kN, static C0 1900 kN, fatigue limit Pu 176 kN, limiting speed 1,200 r/min, reference speed 1,100 r/min, mass about 23000 g."
      },
      {
        "q": "How is the NA 4864 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 320 mm bore, 80 mm width, 400 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4864 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4864 carries its own hardened, ground inner ring on a 320 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4864-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 320×400×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4864",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4864",
      "NA 4864"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4868",
    "brand": "SKF",
    "manufacturer_designation": "NA 4868",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 340,
    "D_mm": 420,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 616,
    "static_load_kN": 1960,
    "fatigue_load_limit_kN": 183,
    "max_rpm": 1200,
    "reference_speed_rpm": 1000,
    "limiting_speed_rpm": 1200,
    "weight_g": 24000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "SKF lists NA 4868 in the dimension series 48 needle roller bearings with inner ring with boundary dimensions 340×420×80 mm: an inner ring turns on the shaft while the flanged outer ring carries the needle roller complement in the housing. The NA 4868 code gives bore 340 mm and width 80 mm explicitly; unlike the RNA/NK families the shaft only needs a standard k5/j5 seat because the hardened inner ring is the raceway. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 616 kN against C0 1960 kN gives a C0/C ratio of 3.18, and the 183 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Because the inner ring is separable, mount it first against its shoulder, then slide the outer ring and roller set over it — the order avoids forcing rollers across the shaft threads or burrs.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "inner-ring bore fretting on a loose shaft seat, migrating hard particles into the rolling contact"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 340 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 616/1960 kN ratings and 24000 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 648); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NA 4868?",
        "a": "A NA 4868 measures 340 mm bore/Fw × 420 mm outside diameter × 80 mm width (13.386 × 16.535 × 3.15 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 616 kN, static C0 1960 kN, fatigue limit Pu 183 kN, limiting speed 1,200 r/min, reference speed 1,000 r/min, mass about 24000 g."
      },
      {
        "q": "How is the NA 4868 designation read?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 340 mm bore, 80 mm width, 420 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Can the NA 4868 run on an unhardened shaft?",
        "a": "Yes — that is the point of this family. The NA 4868 carries its own hardened, ground inner ring on a 340 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      },
      {
        "q": "How should the NA 4868 be mounted?",
        "a": "Mount the inner ring on the 340 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4868-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 340×420×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4868",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4868",
      "NA 4868"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4872",
    "brand": "SKF",
    "manufacturer_designation": "NA 4872",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 360,
    "D_mm": 440,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 627,
    "static_load_kN": 2040,
    "fatigue_load_limit_kN": 186,
    "max_rpm": 1100,
    "reference_speed_rpm": 950,
    "limiting_speed_rpm": 1100,
    "weight_g": 25500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "The dimension series 48 needle roller bearings with inner ring execution NA 4872 measures 360×440×80 mm: needle rollers caged between a flanged outer ring and a ground inner ring, used wherever the journal cannot serve as a raceway. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 360 mm bore (d), 80 mm width; the 440 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 627 kN against C0 2040 kN gives a C0/C ratio of 3.25, and the 186 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 360 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 80 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 360 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NA 4872 shares its 360×440×80 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 627/2040 kN ratings and 25500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 648); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NA 4872?",
        "a": "Mount the inner ring on the 360 mm seat first (induction heat, max 120 °C, or press), then fit the flanged outer ring into the H7 housing bore. Verify free rotation and, for 2RS executions, check the wider outer ring against the housing depth."
      },
      {
        "q": "Is the NA 4872 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4872 have?",
        "a": "A NA 4872 measures 360 mm bore/Fw × 440 mm outside diameter × 80 mm width (14.173 × 17.323 × 3.15 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 627 kN, static C0 2040 kN, fatigue limit Pu 186 kN, limiting speed 1,100 r/min, reference speed 950 r/min, mass about 25500 g."
      },
      {
        "q": "What does NA 4872 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 360 mm bore, 80 mm width, 440 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4872-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 360×440×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4872",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4872",
      "NA 4872"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NA4876",
    "brand": "SKF",
    "manufacturer_designation": "NA 4876",
    "series": "NA-48-series",
    "type": "needle",
    "d_mm": 380,
    "D_mm": 480,
    "B_mm": 100,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 968,
    "static_load_kN": 3000,
    "fatigue_load_limit_kN": 270,
    "max_rpm": 1000,
    "reference_speed_rpm": 900,
    "limiting_speed_rpm": 1000,
    "weight_g": 42500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 1206",
    "naming_rule_text": "For a 380 mm shaft that cannot be hardened on site, NA 4876 adds a hardened, ground inner ring to the machined needle roller design: envelope 380×480×100 mm per the dimension series 48 needle roller bearings with inner ring plan. Reading the designation: the letters name the series with inner ring, the numbers the boundary plan — 380 mm bore (d), 100 mm width; the 480 mm OD follows the dimension series, and the inner ring is a separate ground component. Execution notes: the inner ring is ground on bore and raceway, so the shaft seat is a normal k5/j6; the flanged outer ring needs no housing shoulder, and NA 49 2RS executions add seals with a wider outer ring. Selection arithmetic: C 968 kN against C0 3000 kN gives a C0/C ratio of 3.10, and the 270 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: heat or press the inner ring onto the 380 mm k5 seat (max 120 °C), fit the flanged outer ring into the H7 housing bore, and check the 100 mm assembly for free rotation before applying load.",
    "applications": [
      "gearbox shafts where the journal cannot be hardened on site",
      "wheel and lever pivots needing a replaceable inner ring",
      "conveyor roller ends and return rollers",
      "agricultural implement pivots and cutter heads"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "inner-ring raceway spalling after the narrow ring section runs hot with excessive interference"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 380 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 900 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 380 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 968/3000 kN ratings and 42500 g mass are SKF catalogue values transcribed from ch. 7.4 of PUB BU/P1 17000 (PDF table page 648); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NA 4876 sealed?",
        "a": "No — the open execution relies on housing seals; 2RS executions of the 49 series add contact seals with a wider outer ring as a separate order number."
      },
      {
        "q": "Which dimensions does the NA 4876 have?",
        "a": "A NA 4876 measures 380 mm bore/Fw × 480 mm outside diameter × 100 mm width (14.961 × 18.898 × 3.937 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 968 kN, static C0 3000 kN, fatigue limit Pu 270 kN, limiting speed 1,000 r/min, reference speed 900 r/min, mass about 42500 g."
      },
      {
        "q": "What does NA 4876 mean in SKF part numbering?",
        "a": "The letters mark a machined-ring needle roller bearing with inner ring: 380 mm bore, 100 mm width, 480 mm OD per the series plan. The hardened inner ring is the raceway, so an ordinary k5 shaft seat suffices."
      },
      {
        "q": "Does the NA 4876 need a hardened and ground shaft?",
        "a": "Yes — that is the point of this family. The NA 4876 carries its own hardened, ground inner ring on a 380 mm seat, so the shaft needs only a normal k5/j6 finish. The inner ring is separable and replaceable."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4876-XL",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 380×480×100 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "NA4876",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.4 machined rings with flanges, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NA4876",
      "NA 4876"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA15-28",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 15/28",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.37,
    "static_load_kN": 9.15,
    "fatigue_load_limit_kN": 1.08,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where a plain needle roller bearing would edge-load on a bent frame, RPNA 15/28 from the self-aligning needle roller bearings without inner ring aligns itself: 15 mm bore, 28 mm sphered outside diameter, 12 mm width. Reading the designation: RPNA marks the self-aligning execution ( inner ring), the numbers giving 15 mm bore and 12 mm width; the sphered outside diameter 28 mm follows the series plan. Execution notes: alignment comes from the convex outer ring outside surface running in a plain sphered seat — no separate self-aligning washer is needed, and roughly ±2° of static seat error is absorbed. Speed planning separates the two ceilings: 24,000 r/min thermal reference and 28,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 15 mm seat. Retain the ring axially with washers spanning the full outside surface; point clamps that dig into the sphered surface flatten it and spoil the alignment travel.",
    "applications": [
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 7.37/9.15 kN ratings are SKF catalogue values for this exact execution (RPNA 15/28); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 7.37/9.15 kN ratings and 32 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the RPNA 15/28 have?",
        "a": "A RPNA 15/28 measures 15 mm bore/Fw × 28 mm outside diameter × 12 mm width (0.591 × 1.102 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.37 kN, static C0 9.15 kN, fatigue limit Pu 1.08 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 32 g."
      },
      {
        "q": "What does RPNA 15/28 mean in SKF part numbering?",
        "a": "RPNA marks the self-aligning needle roller family (with machined rings): figures give the 15 mm seat and 12 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Does the RPNA 15/28 need a hardened and ground shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 15 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "What mounting mistakes ruin a RPNA 15/28?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA15-28",
      "RPNA 15/28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA18-32",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 18/32",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 18,
    "D_mm": 32,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 17.6,
    "fatigue_load_limit_kN": 2.12,
    "max_rpm": 24000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 24000,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "RPNA 18/32 is a self-aligning needle roller bearing: a heavy machined outer ring with a convex outside surface seated against an aligning ring, absorbing housing misalignment around a 18 mm raceway, as listed in SKF catalogue PUB BU/P1 17000. Reading the designation: RPNA marks the self-aligning execution ( inner ring), the numbers giving 18 mm bore and 16 mm width; the sphered outside diameter 32 mm follows the series plan. The alignment range is meant for static seat errors, not continuous swivelling under load — dynamic pivoting races the sphered surface and requires grease with extreme-pressure additives. Catalogue mass 52 g at 18×32×16 mm makes this one of the highest capacity-per-gram choices in the self-aligning needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Retain the ring axially with washers spanning the full outside surface; point clamps that dig into the sphered surface flatten it and spoil the alignment travel.",
    "applications": [
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "On a 18 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 12.8/17.6 kN ratings are SKF catalogue values for this exact execution (RPNA 18/32); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 12.8/17.6 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the RPNA 18/32 need a hardened and ground shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 18 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "What mounting mistakes ruin a RPNA 18/32?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 18 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RPNA 18/32 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the RPNA 18/32 have?",
        "a": "A RPNA 18/32 measures 18 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.709 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.8 kN, static C0 17.6 kN, fatigue limit Pu 2.12 kN, limiting speed 24,000 r/min, reference speed 22,000 r/min, mass about 52 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA18",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA18-32",
      "RPNA 18/32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA20-35",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 20/35",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 35,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 19.3,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 62,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "RPNA 20/35 is a self-aligning needle roller bearing: a heavy machined outer ring with a convex outside surface seated against an aligning ring, absorbing housing misalignment around a 20 mm raceway, as listed in SKF catalogue PUB BU/P1 17000. In SKF nomenclature the P in RPNA flags the pivoting, sphered outer ring; dimensions 20×35×16 mm follow the heavy-section plan, and the inner ring decision is fixed by the family letter. Execution notes: alignment comes from the convex outer ring outside surface running in a plain sphered seat — no separate self-aligning washer is needed, and roughly ±2° of static seat error is absorbed. The 62 g catalogue mass and 7.5 mm radial section ((35−20)/2) frame a rating of about 0.66 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 20 mm raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 35 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: RPNA 20/35 shares its 20×35×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 13.2/19.3 kN ratings and 62 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RPNA 20/35 mean in SKF part numbering?",
        "a": "RPNA marks the self-aligning needle roller family (with machined rings): figures give the 20 mm seat and 16 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Does the RPNA 20/35 need a hardened and ground shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 20 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "What mounting mistakes ruin a RPNA 20/35?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RPNA 20/35 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA20",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA20-35",
      "RPNA 20/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA25-42",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 25/42",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 18000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 18000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "RPNA 25/42 combines machined-ring needle roller capacity with self-alignment: 25×42×20 mm envelope, convex outer-ring outside running in a correspondingly sphered washer or housing seat. The code RPNA 25/42 reads as alignment needle roller bearing, 25 mm bore, 20 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. Catalogue mass 110 g at 25×42×20 mm makes this one of the highest capacity-per-gram choices in the self-aligning needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The sphered seat must be clean and lightly oiled — a scored seat converts the alignment feature into a friction lock, and the needle rollers then take the seat error the family was meant to absorb.",
    "applications": [
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 19/32.5 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the RPNA 25/42 designation read?",
        "a": "RPNA marks the self-aligning needle roller family (with machined rings): figures give the 25 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Can the RPNA 25/42 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 25 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the RPNA 25/42 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RPNA 25/42?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA25-42",
      "RPNA 25/42"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA30-47",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 30/47",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "RPNA 30/47 combines machined-ring needle roller capacity with self-alignment: 30×47×20 mm envelope, convex outer-ring outside running in a correspondingly sphered washer or housing seat. The RPNA 30/47 figures state the 30 mm seat and 20 mm width; the letters carry the construction — machined rings, integral flanges, and the convex outside surface that aligns inside its seat. Execution notes: alignment comes from the convex outer ring outside surface running in a plain sphered seat — no separate self-aligning washer is needed, and roughly ±2° of static seat error is absorbed. Catalogue mass 130 g at 30×47×20 mm makes this one of the highest capacity-per-gram choices in the self-aligning needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 30 mm raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 22.9/38 kN ratings are SKF catalogue values for this exact execution (RPNA 30/47); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 22.9/38 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RPNA 30/47 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 30 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the RPNA 30/47 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RPNA 30/47?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RPNA 30/47?",
        "a": "A RPNA 30/47 measures 30 mm bore/Fw × 47 mm outside diameter × 20 mm width (1.181 × 1.85 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 130 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA30-47",
      "RPNA 30/47"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA35-52",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 35/52",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 52,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies RPNA 35/52 for pivots whose housings distort under load: the needle roller ring rides on a spherical seat, keeping edge loads off the 20 mm wide roller complement. The code RPNA 35/52 reads as alignment needle roller bearing, 35 mm bore, 20 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. The alignment range is meant for static seat errors, not continuous swivelling under load — dynamic pivoting races the sphered surface and requires grease with extreme-pressure additives. The 130 g catalogue mass and 8.5 mm radial section ((52−35)/2) frame a rating of about 0.70 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 35 mm raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 24.6/45 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the RPNA 35/52 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RPNA 35/52?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RPNA 35/52?",
        "a": "A RPNA 35/52 measures 35 mm bore/Fw × 52 mm outside diameter × 20 mm width (1.378 × 2.047 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 130 g."
      },
      {
        "q": "How is the RPNA 35/52 designation read?",
        "a": "RPNA marks the self-aligning needle roller family (with machined rings): figures give the 35 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA35",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA35-52",
      "RPNA 35/52"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA40-55",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 40/55",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, RPNA 40/55 denotes an alignment needle roller bearing for a 40 mm shaft: machined rings, integral flanges, and a spherical outside surface that compensates static misalignment of the housing bore. The code RPNA 40/55 reads as alignment needle roller bearing, 40 mm bore, 20 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. For life calculation, the 26.4/51 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 40 mm raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 26.4/51 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the RPNA 40/55 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 40 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the RPNA 40/55 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a RPNA 40/55?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the RPNA 40/55?",
        "a": "A RPNA 40/55 measures 40 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.575 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 140 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI40-20-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×55×20 mm envelope, but catalogue C/C0 differ between the executions (26.4/51 vs 31.4/65.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA40-55",
      "RPNA 40/55"
    ],
    "locale_variants": {}
  },
  {
    "sku": "RPNA45-62",
    "brand": "SKF",
    "manufacturer_designation": "RPNA 45/62",
    "series": "RPNA-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 62,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where a plain needle roller bearing would edge-load on a bent frame, RPNA 45/62 from the self-aligning needle roller bearings without inner ring aligns itself: 45 mm bore, 62 mm sphered outside diameter, 20 mm width. Reading the designation: RPNA marks the self-aligning execution ( inner ring), the numbers giving 45 mm bore and 20 mm width; the sphered outside diameter 62 mm follows the series plan. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. Catalogue mass 180 g at 45×62×20 mm makes this one of the highest capacity-per-gram choices in the self-aligning needle roller bearings without inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 45 mm raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 27.5/57 kN ratings are SKF catalogue values for this exact execution (RPNA 45/62); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The 27.5/57 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.5 of PUB BU/P1 17000 (PDF table page 650); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does RPNA 45/62 mean in SKF part numbering?",
        "a": "RPNA marks the self-aligning needle roller family (with machined rings): figures give the 45 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Does the RPNA 45/62 need a hardened and ground shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 45 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "What mounting mistakes ruin a RPNA 45/62?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the RPNA 45/62 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "RPNA45",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.5 alignment needle roller bearings, without an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "RPNA45-62",
      "RPNA 45/62"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA12-28",
    "brand": "SKF",
    "manufacturer_designation": "PNA 12/28",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 7.37,
    "static_load_kN": 9.15,
    "fatigue_load_limit_kN": 1.08,
    "max_rpm": 28000,
    "reference_speed_rpm": 24000,
    "limiting_speed_rpm": 28000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The self-aligning needle roller bearings with inner ring execution PNA 12/28 pairs a flanged needle roller ring (12 mm inner-ring 28 mm OD, 12 mm wide) with a sphered seat: the outer ring swivels a few degrees to follow frame deflection. In SKF nomenclature the P in PNA flags the pivoting, sphered outer ring; dimensions 12×28×12 mm follow the heavy-section plan, and the inner-ring inner ring decision is fixed by the family letter. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. Speed planning separates the two ceilings: 24,000 r/min thermal reference and 28,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 12 mm seat. Retain the ring axially with washers spanning the full outside surface; point clamps that dig into the sphered surface flatten it and spoil the alignment travel.",
    "applications": [
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 24,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 7.37/9.15 kN ratings and 37 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the PNA 12/28 need a hardened and ground shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 12 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "What mounting mistakes ruin a PNA 12/28?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 12 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the PNA 12/28 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the PNA 12/28 have?",
        "a": "A PNA 12/28 measures 12 mm bore/Fw × 28 mm outside diameter × 12 mm width (0.472 × 1.102 × 0.472 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 7.37 kN, static C0 9.15 kN, fatigue limit Pu 1.08 kN, limiting speed 28,000 r/min, reference speed 24,000 r/min, mass about 37 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA12",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA12-28",
      "PNA 12/28"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA15-32",
    "brand": "SKF",
    "manufacturer_designation": "PNA 15/32",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 17.6,
    "fatigue_load_limit_kN": 2.12,
    "max_rpm": 24000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 24000,
    "weight_g": 62,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "PNA 15/32 combines machined-ring needle roller capacity with self-alignment: 15×32×16 mm envelope, convex outer-ring outside running in a correspondingly sphered washer or housing seat. The code PNA 15/32 reads as alignment needle roller bearing, 15 mm inner-ring bore, 16 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. Minimum load matters: below roughly 0.02·C the rollers skid and smear; preloading the pivot or specifying a heavier execution avoids the glazing that pure oscillation produces on these raceways. The sphered seat must be clean and lightly oiled — a scored seat converts the alignment feature into a friction lock, and the needle rollers then take the seat error the family was meant to absorb.",
    "applications": [
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 32 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: PNA 15/32 shares its 15×32×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 12.8/17.6 kN ratings and 62 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a PNA 15/32?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the PNA 15/32?",
        "a": "A PNA 15/32 measures 15 mm bore/Fw × 32 mm outside diameter × 16 mm width (0.591 × 1.26 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.8 kN, static C0 17.6 kN, fatigue limit Pu 2.12 kN, limiting speed 24,000 r/min, reference speed 22,000 r/min, mass about 62 g."
      },
      {
        "q": "How is the PNA 15/32 designation read?",
        "a": "PNA marks the self-aligning needle roller family (inner-ring with machined rings): figures give the 15 mm seat and 16 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Can the PNA 15/32 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 15 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA15",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA15-32",
      "PNA 15/32"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA17-35",
    "brand": "SKF",
    "manufacturer_designation": "PNA 17/35",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 35,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 19.3,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 73,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies PNA 17/35 for pivots whose housings distort under load: the needle roller ring inner-ring rides on a spherical seat, keeping edge loads off the 16 mm wide roller complement. The code PNA 17/35 reads as alignment needle roller bearing, 17 mm inner-ring bore, 16 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. For life calculation, the 13.2/19.3 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Retain the ring axially with washers spanning the full outside surface; point clamps that dig into the sphered surface flatten it and spoil the alignment travel.",
    "applications": [
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 35 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: PNA 17/35 shares its 17×35×16 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 13.2/19.3 kN ratings and 73 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the PNA 17/35 designation read?",
        "a": "PNA marks the self-aligning needle roller family (inner-ring with machined rings): figures give the 17 mm seat and 16 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Can the PNA 17/35 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 17 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the PNA 17/35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a PNA 17/35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 9.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA17",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA17-35",
      "PNA 17/35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA20-42",
    "brand": "SKF",
    "manufacturer_designation": "PNA 20/42",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 18000,
    "reference_speed_rpm": 16000,
    "limiting_speed_rpm": 18000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The self-aligning needle roller bearings with inner ring execution PNA 20/42 pairs a flanged needle roller ring (20 mm inner-ring 42 mm OD, 20 mm wide) with a sphered seat: the outer ring swivels a few degrees to follow frame deflection. Reading the designation: PNA marks the self-aligning execution (inner-ring  inner ring), the numbers giving 20 mm inner-ring bore and 20 mm width; the sphered outside diameter 42 mm follows the series plan. The alignment range is meant for static seat errors, not continuous swivelling under load — dynamic pivoting races the sphered surface and requires grease with extreme-pressure additives. Selection arithmetic: C 19 kN against C0 32.5 kN gives a C0/C ratio of 1.71, and the 4 kN fatigue load limit Pu sets the floor for the adjusted-life calculation at contaminated lubrication. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 20 mm inner-ring raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: PNA 20/42 shares its 20×42×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The 19/32.5 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a PNA 20/42?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the PNA 20/42 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the PNA 20/42 have?",
        "a": "A PNA 20/42 measures 20 mm bore/Fw × 42 mm outside diameter × 20 mm width (0.787 × 1.654 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 18,000 r/min, reference speed 16,000 r/min, mass about 140 g."
      },
      {
        "q": "What does PNA 20/42 mean in SKF part numbering?",
        "a": "PNA marks the self-aligning needle roller family (inner-ring with machined rings): figures give the 20 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIS20",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×20 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 28.6/39 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA20-42",
      "PNA 20/42"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA22-44",
    "brand": "SKF",
    "manufacturer_designation": "PNA 22/44",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 44,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 4.55,
    "max_rpm": 16000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 16000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, PNA 22/44 denotes an alignment needle roller bearing for a 22 mm inner-ring shaft: machined rings, integral flanges, and a spherical outside surface that compensates static misalignment of the housing bore. The code PNA 22/44 reads as alignment needle roller bearing, 22 mm inner-ring bore, 20 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. Catalogue mass 150 g at 22×44×20 mm makes this one of the highest capacity-per-gram choices in the self-aligning needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 22 mm inner-ring raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 44 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: PNA 22/44 shares its 22×44×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 14,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "The 22/36.5 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the PNA 22/44 designation read?",
        "a": "PNA marks the self-aligning needle roller family (inner-ring with machined rings): figures give the 22 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Can the PNA 22/44 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 22 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the PNA 22/44 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a PNA 22/44?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 22 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA22",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA22-44",
      "PNA 22/44"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA25-47",
    "brand": "SKF",
    "manufacturer_designation": "PNA 25/47",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 47,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "PNA 25/47 combines machined-ring needle roller capacity with self-alignment: 25×47×20 mm envelope, convex outer-ring outside running in a correspondingly sphered washer or housing seat. Reading the designation: PNA marks the self-aligning execution (inner-ring  inner ring), the numbers giving 25 mm inner-ring bore and 20 mm width; the sphered outside diameter 47 mm follows the series plan. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. The 160 g catalogue mass and 11.0 mm radial section ((47−25)/2) frame a rating of about 0.92 kN dynamic per millimetre of bore — the needle construction's density advantage over ball bearings of the same envelope. The sphered seat must be clean and lightly oiled — a scored seat converts the alignment feature into a friction lock, and the needle rollers then take the seat error the family was meant to absorb.",
    "applications": [
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 47 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 13,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The 22.9/38 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the PNA 25/47 need a hardened and ground shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 25 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "What mounting mistakes ruin a PNA 25/47?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the PNA 25/47 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the PNA 25/47 have?",
        "a": "A PNA 25/47 measures 25 mm bore/Fw × 47 mm outside diameter × 20 mm width (0.984 × 1.85 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 160 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA25",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA25-47",
      "PNA 25/47"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA30-52",
    "brand": "SKF",
    "manufacturer_designation": "PNA 30/52",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 52,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, PNA 30/52 denotes an alignment needle roller bearing for a 30 mm inner-ring shaft: machined rings, integral flanges, and a spherical outside surface that compensates static misalignment of the housing bore. The PNA 30/52 figures state the 30 mm seat and 20 mm width; the letters carry the construction — machined rings, integral flanges, and the convex outside surface that aligns inside its seat. These are heavy-section machined rings, not drawn cups: the sphered outside surface is ground, the flanges retain the rollers, and the PNA execution adds the ground inner ring for unhardened shafts. For life calculation, the 24.6/45 kN ratings assume raceway geometry supplied by the shaft and housing in families without an inner ring — journal hardness, roundness and finish are part of the bearing, not of the application. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 30 mm inner-ring raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load",
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 24.6/45 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the PNA 30/52 designation read?",
        "a": "PNA marks the self-aligning needle roller family (inner-ring with machined rings): figures give the 30 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Can the PNA 30/52 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 30 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the PNA 30/52 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a PNA 30/52?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA30",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA30-52",
      "PNA 30/52"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA35-55",
    "brand": "SKF",
    "manufacturer_designation": "PNA 35/55",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, PNA 35/55 denotes an alignment needle roller bearing for a 35 mm inner-ring shaft: machined rings, integral flanges, and a spherical outside surface that compensates static misalignment of the housing bore. The code PNA 35/55 reads as alignment needle roller bearing, 35 mm inner-ring bore, 20 mm width — the wide section is what absorbs both load and the seat-angle errors the family is designed for. The alignment range is meant for static seat errors, not continuous swivelling under load — dynamic pivoting races the sphered surface and requires grease with extreme-pressure additives. Catalogue mass 180 g at 35×55×20 mm makes this one of the highest capacity-per-gram choices in the self-aligning needle roller bearings with inner ring; the limit is usually the shaft's ability to serve as a raceway, not the rolling contact itself. The sphered seat must be clean and lightly oiled — a scored seat converts the alignment feature into a friction lock, and the needle rollers then take the seat error the family was meant to absorb.",
    "applications": [
      "construction equipment blade and arm pivots",
      "steering knuckles and kingpin supports with seat angle errors",
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 26.4/51 kN ratings are SKF catalogue values for this exact execution (PNA 35/55); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The 26.4/51 kN ratings and 180 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the PNA 35/55 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 35 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      },
      {
        "q": "How should the PNA 35/55 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a PNA 35/55?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the PNA 35/55?",
        "a": "A PNA 35/55 measures 35 mm bore/Fw × 55 mm outside diameter × 20 mm width (1.378 × 2.165 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 11,000 r/min, reference speed 10,000 r/min, mass about 180 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NA4907",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×20 mm envelope, but catalogue C/C0 differ between the executions (26.4/51 vs 31.9/54 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA35-55",
      "PNA 35/55"
    ],
    "locale_variants": {}
  },
  {
    "sku": "PNA40-62",
    "brand": "SKF",
    "manufacturer_designation": "PNA 40/62",
    "series": "PNA-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 10000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 10000,
    "weight_g": 230,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "PNA 40/62 combines machined-ring needle roller capacity with self-alignment: 40×62×20 mm envelope, convex outer-ring outside running in a correspondingly sphered washer or housing seat. The PNA 40/62 figures state the 40 mm seat and 20 mm width; the letters carry the construction — machined rings, integral flanges, and the convex outside surface that aligns inside its seat. Execution notes: alignment comes from the convex outer ring outside surface running in a plain sphered seat — no separate self-aligning washer is needed, and roughly ±2° of static seat error is absorbed. Speed planning separates the two ceilings: 9,000 r/min thermal reference and 10,000 r/min mechanical limiting — needle bearings tolerate high rpm only with adequate lubricant film at the 40 mm seat. Mounting: seat the convex outer ring surface in its sphered counterpart dry first, confirm the 40 mm inner-ring raceway rotates freely through the full alignment range, then lubricate and assemble for service.",
    "applications": [
      "pivot bearings where housing bores cannot be kept coaxial",
      "linkage eyes and clevis mounts on frames that flex",
      "agricultural machinery joints exposed to frame distortion",
      "door and gate hinges with heavy radial load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The 27.5/57 kN ratings and 230 g mass are SKF catalogue values transcribed from ch. 7.6 of PUB BU/P1 17000 (PDF table page 652); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a PNA 40/62?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the PNA 40/62?",
        "a": "A PNA 40/62 measures 40 mm bore/Fw × 62 mm outside diameter × 20 mm width (1.575 × 2.441 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 57 kN, fatigue limit Pu 7.1 kN, limiting speed 10,000 r/min, reference speed 9,000 r/min, mass about 230 g."
      },
      {
        "q": "How is the PNA 40/62 designation read?",
        "a": "PNA marks the self-aligning needle roller family (inner-ring with machined rings): figures give the 40 mm seat and 20 mm width; the convex outer-ring outside surface aligns within roughly ±2° in its sphered seat."
      },
      {
        "q": "Can the PNA 40/62 run on an unhardened shaft?",
        "a": "Depends on the family member: RPNA runs directly on the shaft (hardened, 58–64 HRC, ground), while PNA includes a ground inner ring for an ordinary 40 mm k5 seat. Both add the sphered outer ring for seat misalignment."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "PNA40",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.6 alignment needle roller bearings, with an inner ring",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "PNA40-62",
      "PNA 40/62"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5901",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5901",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.09,
    "static_load_kN": 9.65,
    "fatigue_load_limit_kN": 1.14,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5901 is the combined needle roller / angular contact ball bearings entry for a 12 mm shaft: needle rollers run the radial load while the angular contact ball set takes axial force primarily in one direction, in a single machined envelope of 12×24×16 mm. The NKIA 5901 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 12 mm; the 16 mm width covers both the roller cage and the offset ball set (offset per catalogue s column). The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 22,000 r/min thermal reference and 26,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 8.09/9.65 kN ratings are SKF catalogue values for this exact execution (NKIA 5901); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 8.09/9.65 kN ratings and 40 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKIA 5901?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 12 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIA 5901?",
        "a": "A NKIA 5901 measures 12 mm bore/Fw × 24 mm outside diameter × 16 mm width (0.472 × 0.945 × 0.63 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.09 kN, static C0 9.65 kN, fatigue limit Pu 1.14 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 40 g. Axial ratings of the ball part: dynamic Ca 2.07 kN (Ca), static C0a 1.92 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "How is the NKIA 5901 designation read?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595901 gives the series and 12 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 16 mm overall width."
      },
      {
        "q": "Can the NKIA 5901 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIA 5901 rides directly on the 12 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKI12-16",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×16 mm envelope, but catalogue C/C0 differ between the executions (8.09/9.65 vs 11.7/15.3 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5901",
      "NKIA 5901"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5901",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5901",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 17.5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 8.09,
    "static_load_kN": 9.65,
    "fatigue_load_limit_kN": 1.14,
    "max_rpm": 26000,
    "reference_speed_rpm": 22000,
    "limiting_speed_rpm": 26000,
    "weight_g": 43,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIB 5901 among the combined needle roller / three-point contact ball bearings: radial capacity from the needle roller set (8.09 kN C), axial capacity from the three-point contact ball part 2.07 kN (Ca), all within a 24×17.5 mm outline. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 595901 the heavy 59 dimension series around the 12 mm bore. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 22,000 r/min thermal reference and 26,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 17.5 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 22,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 12 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5901 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 8.09/9.65 kN ratings and 43 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKIB 5901 have?",
        "a": "A NKIB 5901 measures 12 mm bore/Fw × 24 mm outside diameter × 17.5 mm width (0.472 × 0.945 × 0.689 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 8.09 kN, static C0 9.65 kN, fatigue limit Pu 1.14 kN, limiting speed 26,000 r/min, reference speed 22,000 r/min, mass about 43 g. Axial ratings of the ball part: dynamic Ca 2.07 kN (Ca), static C0a 1.92 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "What does NKIB 5901 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595901 gives the series and 12 mm bore. The offset (s 16 mm) positions the ball raceway inside the 17.5 mm overall width."
      },
      {
        "q": "Does the NKIB 5901 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 5901 rides directly on the 12 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIB 5901?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 12 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5901",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5901",
      "NKIB 5901"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5902",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5902",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.2,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.83,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5902 is a combined needle roller / angular ball bearing: one unit carrying radial load on the needle roller set and one-direction-leaning axial load on the ball set, 15×28×18 mm, listed by SKF in SKF catalogue PUB BU/P1 17000. In SKF nomenclature NKIA denotes the combined construction and 595902 the series/bore; the ball raceway sits offset on the inner ring, which is why the 18 mm overall width is greater than a plain needle bearing of the same bore. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 11.2 kN, radial C0 15.3 kN, axial dynamic 2.27 kN (Ca) and axial static 2.37 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 5902 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 11.2/15.3 kN ratings and 50 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKIA 5902?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIA 5902 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIA 5902 have?",
        "a": "A NKIA 5902 measures 15 mm bore/Fw × 28 mm outside diameter × 18 mm width (0.591 × 1.102 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.2 kN, static C0 15.3 kN, fatigue limit Pu 1.83 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 50 g. Axial ratings of the ball part: dynamic Ca 2.27 kN (Ca), static C0a 2.37 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "What does NKIA 5902 mean in SKF part numbering?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595902 gives the series and 15 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 18 mm overall width."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5902",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5902",
      "NKIA 5902"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5902",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5902",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.2,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.83,
    "max_rpm": 22000,
    "reference_speed_rpm": 19000,
    "limiting_speed_rpm": 22000,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For shafts where a separate thrust bearing would lengthen the assembly, NKIB 5902 integrates needle rollers and an three-point contact ball bearing: 15 mm bore, 28 mm OD, 20 mm overall width including the ball set offset. The NKIB 5902 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 15 mm; the 20 mm width covers both the roller cage and the offset ball set (s offset 18 mm). NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 11.2 kN, radial C0 15.3 kN, axial dynamic 2.27 kN (Ca) and axial static 2.37 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 20 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 28 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKIB 5902 shares its 15×28×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 19,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Do not treat the axial rating 2.27 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5902 facing the working thrust.",
      "The 11.2/15.3 kN ratings and 52 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKIB 5902?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIB 5902?",
        "a": "A NKIB 5902 measures 15 mm bore/Fw × 28 mm outside diameter × 20 mm width (0.591 × 1.102 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.2 kN, static C0 15.3 kN, fatigue limit Pu 1.83 kN, limiting speed 22,000 r/min, reference speed 19,000 r/min, mass about 52 g. Axial ratings of the ball part: dynamic Ca 2.27 kN (Ca), static C0a 2.37 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "How is the NKIB 5902 designation read?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595902 gives the series and 15 mm bore. The offset (s 18 mm) positions the ball raceway inside the 20 mm overall width."
      },
      {
        "q": "Can the NKIB 5902 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIB 5902 rides directly on the 15 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5902",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5902",
      "NKIB 5902"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5903",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5903",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.4,
    "static_load_kN": 16.3,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 56,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKIA 5903 designates a combined bearing of the combined needle roller / angular contact ball bearings: caged needle rollers for the 17 mm radial seat share a shaft with an integral angular contact ball set rated 2.24 kN (Ca) axially. The designation NKIA 5903 identifies the two rolling elements in one unit; the 17 mm bore and 30 mm OD come from the 59-series plan, and the 18 mm width stacks roller set plus ball set. Execution notes: the ball set runs on a raceway offset by a catalogue-listed offset from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Speed ceilings differ by part: 18,000 r/min thermal reference and 20,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKIA 5903 shares its 17×30×18 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 18,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Do not treat the axial rating 2.24 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 5903 facing the working thrust.",
      "The 11.4/16.3 kN ratings and 56 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKIA 5903 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIA 5903 rides directly on the 17 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIA 5903 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIA 5903?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIA 5903?",
        "a": "A NKIA 5903 measures 17 mm bore/Fw × 30 mm outside diameter × 18 mm width (0.669 × 1.181 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.4 kN, static C0 16.3 kN, fatigue limit Pu 1.96 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 56 g. Axial ratings of the ball part: dynamic Ca 2.24 kN (Ca), static C0a 2.74 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5903",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5903",
      "NKIA 5903"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5903",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5903",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11.4,
    "static_load_kN": 16.3,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 20000,
    "reference_speed_rpm": 18000,
    "limiting_speed_rpm": 20000,
    "weight_g": 58,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5903 is the combined needle roller / three-point contact ball bearings entry for a 17 mm shaft: needle rollers run the radial load while the three-point contact ball set takes axial force in both directions through the three-point contact geometry, in a single machined envelope of 17×30×20 mm. In SKF nomenclature NKIB denotes the combined construction and 595903 the series/bore; the ball raceway sits offset on the inner ring, which is why the 20 mm overall width is greater than a plain needle bearing of the same bore. Execution notes: the ball set runs on a raceway offset by s 18 mm from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Speed ceilings differ by part: 18,000 r/min thermal reference and 20,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 20 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIB 5903 shares its 17×30×20 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 2.24 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 11.4/16.3 kN ratings and 58 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKIB 5903?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIB 5903 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIB 5903 have?",
        "a": "A NKIB 5903 measures 17 mm bore/Fw × 30 mm outside diameter × 20 mm width (0.669 × 1.181 × 0.787 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11.4 kN, static C0 16.3 kN, fatigue limit Pu 1.96 kN, limiting speed 20,000 r/min, reference speed 18,000 r/min, mass about 58 g. Axial ratings of the ball part: dynamic Ca 2.24 kN (Ca), static C0a 2.74 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "What does NKIB 5903 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595903 gives the series and 17 mm bore. The offset (s 18 mm) positions the ball raceway inside the 20 mm overall width."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5903",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5903",
      "NKIB 5903"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5904",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5904",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 28,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5904 solves compact radial-plus-thrust duty: a needle roller cage and an angular contact ball bearing built into one 23 mm wide unit with a 20 mm bore and 37 mm outside diameter. Reading the designation: the letters combine the needle roller family with the ball execution — NKIA marks angular contact — and 595904 the heavy 59 dimension series around the 20 mm bore. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Selection arithmetic for the combined unit: radial C 21.6 kN, radial C0 28 kN, axial dynamic 3.79 kN (Ca) and axial static 4.21 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIA 5904 shares its 20×37×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 3.79 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 21.6/28 kN ratings and 100 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKIA 5904 mean in SKF part numbering?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595904 gives the series and 20 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 23 mm overall width."
      },
      {
        "q": "Does the NKIA 5904 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIA 5904 rides directly on the 20 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIA 5904?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIA 5904 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5904",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5904",
      "NKIA 5904"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5904",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5904",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 28,
    "fatigue_load_limit_kN": 3.35,
    "max_rpm": 17000,
    "reference_speed_rpm": 15000,
    "limiting_speed_rpm": 17000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5904 is a combined needle roller / three-point ball bearing: one unit carrying radial load on the needle roller set and one-direction-leaning axial load on the ball set, 20×37×25 mm, listed by SKF in SKF catalogue PUB BU/P1 17000. The designation NKIB 5904 identifies the two rolling elements in one unit; the 20 mm bore and 37 mm OD come from the 59-series plan, and the 25 mm width stacks roller set plus ball set. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Selection arithmetic for the combined unit: radial C 21.6 kN, radial C0 28 kN, axial dynamic 3.79 kN (Ca) and axial static 4.21 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 25 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 21.6/28 kN ratings and 110 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKIB 5904 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIB 5904 rides directly on the 20 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIB 5904 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIB 5904?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 8.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIB 5904?",
        "a": "A NKIB 5904 measures 20 mm bore/Fw × 37 mm outside diameter × 25 mm width (0.787 × 1.457 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 21.6 kN, static C0 28 kN, fatigue limit Pu 3.35 kN, limiting speed 17,000 r/min, reference speed 15,000 r/min, mass about 110 g. Axial ratings of the ball part: dynamic Ca 3.79 kN (Ca), static C0a 4.21 kN (C0a); three-point contact geometry accepts axial load in both directions."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5904",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5904",
      "NKIB 5904"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA59-22",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 59/22",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 39,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.9,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 59/22 solves compact radial-plus-thrust duty: a needle roller cage and an angular contact ball bearing built into one 23 mm wide unit with a 22 mm bore and 39 mm outside diameter. Reading the designation: the letters combine the needle roller family with the ball execution — NKIA marks angular contact — and 5922 the heavy 59 dimension series around the 22 mm bore. Execution notes: the ball set runs on a raceway offset by a catalogue-listed offset from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. The ball set also needs a minimum axial load to keep every ball tracking its raceway under the radial-axial load mix: springs or preload washers are part of the arrangement, not an afterthought. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 23 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 39 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 23.3/32 kN ratings are SKF catalogue values for this exact execution (NKIA 59/22); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Do not treat the axial rating 4.14 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 59/22 facing the working thrust.",
      "The 23.3/32 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKIA 59/22 have?",
        "a": "A NKIA 59/22 measures 22 mm bore/Fw × 39 mm outside diameter × 23 mm width (0.866 × 1.535 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 32 kN, fatigue limit Pu 3.9 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 120 g. Axial ratings of the ball part: dynamic Ca 4.14 kN (Ca), static C0a 4.93 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "What does NKIA 59/22 mean in SKF part numbering?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 5922 gives the series and 22 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 23 mm overall width."
      },
      {
        "q": "Does the NKIA 59/22 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIA 59/22 rides directly on the 22 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIA 59/22?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA59",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA59-22",
      "NKIA 59/22"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB59-22",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 59/22",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 22,
    "D_mm": 39,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 23.3,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 3.9,
    "max_rpm": 15000,
    "reference_speed_rpm": 14000,
    "limiting_speed_rpm": 15000,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 59/22 is the combined needle roller / three-point contact ball bearings entry for a 22 mm shaft: needle rollers run the radial load while the three-point contact ball set takes axial force in both directions through the three-point contact geometry, in a single machined envelope of 22×39×25 mm. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 5922 the heavy 59 dimension series around the 22 mm bore. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Speed ceilings differ by part: 14,000 r/min thermal reference and 15,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: press on the inner ring faces only — the ball set offset (s 23 mm) makes the unit sensitive to bending; support both rings square to the 22 mm seat and never drive through the rolling elements.",
    "applications": [
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force",
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 22 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 39 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIB 59/22 shares its 22×39×25 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 59/22 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 23.3/32 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKIB 59/22 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 59/22 rides directly on the 22 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIB 59/22?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 22 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIB 59/22 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIB 59/22 have?",
        "a": "A NKIB 59/22 measures 22 mm bore/Fw × 39 mm outside diameter × 25 mm width (0.866 × 1.535 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 23.3 kN, static C0 32 kN, fatigue limit Pu 3.9 kN, limiting speed 15,000 r/min, reference speed 14,000 r/min, mass about 120 g. Axial ratings of the ball part: dynamic Ca 4.14 kN (Ca), static C0a 4.93 kN (C0a); three-point contact geometry accepts axial load in both directions."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB59",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB59-22",
      "NKIB 59/22"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5905",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5905",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 34.5,
    "fatigue_load_limit_kN": 4.15,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIA 5905 among the combined needle roller / angular contact ball bearings: radial capacity from the needle roller set (24.2 kN C), axial capacity from the angular contact ball part 4.24 kN (Ca), all within a 42×23 mm outline. The NKIA 5905 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 25 mm; the 23 mm width covers both the roller cage and the offset ball set (offset per catalogue s column). NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Speed ceilings differ by part: 13,000 r/min thermal reference and 15,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 24.2/34.5 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKIA 5905?",
        "a": "A NKIA 5905 measures 25 mm bore/Fw × 42 mm outside diameter × 23 mm width (0.984 × 1.654 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.2 kN, static C0 34.5 kN, fatigue limit Pu 4.15 kN, limiting speed 15,000 r/min, reference speed 13,000 r/min, mass about 130 g. Axial ratings of the ball part: dynamic Ca 4.24 kN (Ca), static C0a 5.26 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "How is the NKIA 5905 designation read?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595905 gives the series and 25 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 23 mm overall width."
      },
      {
        "q": "Can the NKIA 5905 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIA 5905 rides directly on the 25 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIA 5905 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5905",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5905",
      "NKIA 5905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5905",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5905",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 34.5,
    "fatigue_load_limit_kN": 4.15,
    "max_rpm": 15000,
    "reference_speed_rpm": 13000,
    "limiting_speed_rpm": 15000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKIB 5905 designates a combined bearing of the combined needle roller / three-point contact ball bearings: caged needle rollers for the 25 mm radial seat share a shaft with an integral three-point contact ball set rated 4.24 kN (Ca) axially. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 595905 the heavy 59 dimension series around the 25 mm bore. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Speed ceilings differ by part: 13,000 r/min thermal reference and 15,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 25 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 42 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 24.2/34.5 kN ratings are SKF catalogue values for this exact execution (NKIB 5905); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5905 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 24.2/34.5 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKIB 5905 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595905 gives the series and 25 mm bore. The offset (s 23 mm) positions the ball raceway inside the 25 mm overall width."
      },
      {
        "q": "Does the NKIB 5905 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 5905 rides directly on the 25 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIB 5905?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIB 5905 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5905",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5905",
      "NKIB 5905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5906",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5906",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.5,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.65,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For shafts where a separate thrust bearing would lengthen the assembly, NKIA 5906 integrates needle rollers and an angular contact ball bearing: 30 mm bore, 47 mm OD, 23 mm overall width including the ball set offset. In SKF nomenclature NKIA denotes the combined construction and 595906 the series/bore; the ball raceway sits offset on the inner ring, which is why the 23 mm overall width is greater than a plain needle bearing of the same bore. Execution notes: the ball set runs on a raceway offset by a catalogue-listed offset from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Selection arithmetic for the combined unit: radial C 25.5 kN, radial C0 39 kN, axial dynamic 4.54 kN (Ca) and axial static 6.32 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 25.5/39 kN ratings are SKF catalogue values for this exact execution (NKIA 5906); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 5906 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 25.5/39 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKIA 5906 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIA 5906 have?",
        "a": "A NKIA 5906 measures 30 mm bore/Fw × 47 mm outside diameter × 23 mm width (1.181 × 1.85 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 150 g. Axial ratings of the ball part: dynamic Ca 4.54 kN (Ca), static C0a 6.32 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "What does NKIA 5906 mean in SKF part numbering?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595906 gives the series and 30 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 23 mm overall width."
      },
      {
        "q": "Does the NKIA 5906 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIA 5906 rides directly on the 30 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5906",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5906",
      "NKIA 5906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5906",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5906",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 25.5,
    "static_load_kN": 39,
    "fatigue_load_limit_kN": 4.65,
    "max_rpm": 13000,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 13000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5906 solves compact radial-plus-thrust duty: a needle roller cage and an three-point contact ball bearing built into one 25 mm wide unit with a 30 mm bore and 47 mm outside diameter. The NKIB 5906 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 30 mm; the 25 mm width covers both the roller cage and the offset ball set (s offset 23 mm). Execution notes: the ball set runs on a raceway offset by s 23 mm from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Selection arithmetic for the combined unit: radial C 25.5 kN, radial C0 39 kN, axial dynamic 4.54 kN (Ca) and axial static 6.32 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 25 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 25.5/39 kN ratings are SKF catalogue values for this exact execution (NKIB 5906); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 4.54 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5906 facing the working thrust.",
      "The 25.5/39 kN ratings and 150 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKIB 5906?",
        "a": "A NKIB 5906 measures 30 mm bore/Fw × 47 mm outside diameter × 25 mm width (1.181 × 1.85 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 25.5 kN, static C0 39 kN, fatigue limit Pu 4.65 kN, limiting speed 13,000 r/min, reference speed 11,000 r/min, mass about 150 g. Axial ratings of the ball part: dynamic Ca 4.54 kN (Ca), static C0a 6.32 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "How is the NKIB 5906 designation read?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595906 gives the series and 30 mm bore. The offset (s 23 mm) positions the ball raceway inside the 25 mm overall width."
      },
      {
        "q": "Can the NKIB 5906 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIB 5906 rides directly on the 30 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIB 5906 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5906",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5906",
      "NKIB 5906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5907",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5907",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.7,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 240,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5907 is the combined needle roller / angular contact ball bearings entry for a 35 mm shaft: needle rollers run the radial load while the angular contact ball set takes axial force primarily in one direction, in a single machined envelope of 35×55×27 mm. The designation NKIA 5907 identifies the two rolling elements in one unit; the 35 mm bore and 55 mm OD come from the 59-series plan, and the 27 mm width stacks roller set plus ball set. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 9,500 r/min thermal reference and 11,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 31.9/54 kN ratings are SKF catalogue values for this exact execution (NKIA 5907); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 5.83 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 5907 facing the working thrust.",
      "The 31.9/54 kN ratings and 240 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKIA 5907 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIA 5907?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 10.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIA 5907?",
        "a": "A NKIA 5907 measures 35 mm bore/Fw × 55 mm outside diameter × 27 mm width (1.378 × 2.165 × 1.063 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 54 kN, fatigue limit Pu 6.7 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 240 g. Axial ratings of the ball part: dynamic Ca 5.83 kN (Ca), static C0a 8.42 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "How is the NKIA 5907 designation read?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595907 gives the series and 35 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 27 mm overall width."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5907",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5907",
      "NKIA 5907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5907",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5907",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 31.9,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 6.7,
    "max_rpm": 11000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 11000,
    "weight_g": 250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIB 5907 among the combined needle roller / three-point contact ball bearings: radial capacity from the needle roller set (31.9 kN C), axial capacity from the three-point contact ball part 5.83 kN (Ca), all within a 55×30 mm outline. In SKF nomenclature NKIB denotes the combined construction and 595907 the series/bore; the ball raceway sits offset on the inner ring, which is why the 30 mm overall width is greater than a plain needle bearing of the same bore. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 9,500 r/min thermal reference and 11,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 30 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 9,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 5.83 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 31.9/54 kN ratings and 250 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKIB 5907 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIB 5907 have?",
        "a": "A NKIB 5907 measures 35 mm bore/Fw × 55 mm outside diameter × 30 mm width (1.378 × 2.165 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 31.9 kN, static C0 54 kN, fatigue limit Pu 6.7 kN, limiting speed 11,000 r/min, reference speed 9,500 r/min, mass about 250 g. Axial ratings of the ball part: dynamic Ca 5.83 kN (Ca), static C0a 8.42 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "What does NKIB 5907 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595907 gives the series and 35 mm bore. The offset (s 27 mm) positions the ball raceway inside the 30 mm overall width."
      },
      {
        "q": "Does the NKIB 5907 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 5907 rides directly on the 35 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5907",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5907",
      "NKIB 5907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5908",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5908",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 71,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 320,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5908 is a combined needle roller / angular ball bearing: one unit carrying radial load on the needle roller set and one-direction-leaning axial load on the ball set, 40×62×30 mm, listed by SKF in SKF catalogue PUB BU/P1 17000. Reading the designation: the letters combine the needle roller family with the ball execution — NKIA marks angular contact — and 595908 the heavy 59 dimension series around the 40 mm bore. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 42.9 kN, radial C0 71 kN, axial dynamic 7.17 kN (Ca) and axial static 10.9 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 7.17 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 42.9/71 kN ratings and 320 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKIA 5908 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIA 5908 rides directly on the 40 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIA 5908?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIA 5908 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIA 5908 have?",
        "a": "A NKIA 5908 measures 40 mm bore/Fw × 62 mm outside diameter × 30 mm width (1.575 × 2.441 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 71 kN, fatigue limit Pu 8.8 kN, limiting speed 9,500 r/min, reference speed 8,000 r/min, mass about 320 g. Axial ratings of the ball part: dynamic Ca 7.17 kN (Ca), static C0a 10.9 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5908",
      "NKIA 5908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5908",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5908",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 42.9,
    "static_load_kN": 71,
    "fatigue_load_limit_kN": 8.8,
    "max_rpm": 9500,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9500,
    "weight_g": 320,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For shafts where a separate thrust bearing would lengthen the assembly, NKIB 5908 integrates needle rollers and an three-point contact ball bearing: 40 mm bore, 62 mm OD, 34 mm overall width including the ball set offset. The designation NKIB 5908 identifies the two rolling elements in one unit; the 40 mm bore and 62 mm OD come from the 59-series plan, and the 34 mm width stacks roller set plus ball set. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 42.9 kN, radial C0 71 kN, axial dynamic 7.17 kN (Ca) and axial static 10.9 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 34 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NKIB 5908 shares its 40×62×34 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 42.9/71 kN ratings and 320 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKIB 5908 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIB 5908?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIB 5908?",
        "a": "A NKIB 5908 measures 40 mm bore/Fw × 62 mm outside diameter × 34 mm width (1.575 × 2.441 × 1.339 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 42.9 kN, static C0 71 kN, fatigue limit Pu 8.8 kN, limiting speed 9,500 r/min, reference speed 8,000 r/min, mass about 320 g. Axial ratings of the ball part: dynamic Ca 7.17 kN (Ca), static C0a 10.9 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "How is the NKIB 5908 designation read?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595908 gives the series and 40 mm bore. The offset (s 30 mm) positions the ball raceway inside the 34 mm overall width."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5908",
      "NKIB 5908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5909",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5909",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 45.7,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKIA 5909 designates a combined bearing of the combined needle roller / angular contact ball bearings: caged needle rollers for the 45 mm radial seat share a shaft with an integral angular contact ball set rated 7.47 kN (Ca) axially. The NKIA 5909 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 45 mm; the 30 mm width covers both the roller cage and the offset ball set (offset per catalogue s column). Execution notes: the ball set runs on a raceway offset by a catalogue-listed offset from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Speed ceilings differ by part: 7,500 r/min thermal reference and 8,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Do not interchange envelope-identical needle families blindly: NKIA 5909 shares its 45×68×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 45.7/78 kN ratings and 380 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKIA 5909 designation read?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595909 gives the series and 45 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 30 mm overall width."
      },
      {
        "q": "Can the NKIA 5909 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIA 5909 rides directly on the 45 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIA 5909 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIA 5909?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 45 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5909",
      "NKIA 5909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5909",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5909",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 45.7,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5909 is the combined needle roller / three-point contact ball bearings entry for a 45 mm shaft: needle rollers run the radial load while the three-point contact ball set takes axial force in both directions through the three-point contact geometry, in a single machined envelope of 45×68×34 mm. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 595909 the heavy 59 dimension series around the 45 mm bore. Execution notes: the ball set runs on a raceway offset by s 30 mm from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Speed ceilings differ by part: 7,500 r/min thermal reference and 8,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Life-lubricated as supplied in most sizes; where a relubrication path exists, meter grease gently — pressure through the 34 mm wide unit can lift the seals of adjacent components.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIB 5909 shares its 45×68×34 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5909 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 45.7/78 kN ratings and 380 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKIB 5909 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 5909 rides directly on the 45 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIB 5909?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIB 5909 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIB 5909 have?",
        "a": "A NKIB 5909 measures 45 mm bore/Fw × 68 mm outside diameter × 34 mm width (1.772 × 2.677 × 1.339 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 45.7 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 380 g. Axial ratings of the ball part: dynamic Ca 7.47 kN (Ca), static C0a 12 kN (C0a); three-point contact geometry accepts axial load in both directions."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5909",
      "NKIB 5909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5910",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5910",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 47.3,
    "static_load_kN": 85,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKIA 5910 designates a combined bearing of the combined needle roller / angular contact ball bearings: caged needle rollers for the 50 mm radial seat share a shaft with an integral angular contact ball set rated 7.74 kN (Ca) axially. The NKIA 5910 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 50 mm; the 30 mm width covers both the roller cage and the offset ball set (offset per catalogue s column). The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 7,000 r/min thermal reference and 8,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: press on the inner ring faces only — the ball set offset (a catalogue-listed offset) makes the unit sensitive to bending; support both rings square to the 50 mm seat and never drive through the rolling elements.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 47.3/85 kN ratings and 380 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKIA 5910 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIA 5910 rides directly on the 50 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIA 5910 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIA 5910?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 50 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 11.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIA 5910?",
        "a": "A NKIA 5910 measures 50 mm bore/Fw × 72 mm outside diameter × 30 mm width (1.969 × 2.835 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 47.3 kN, static C0 85 kN, fatigue limit Pu 10.6 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 380 g. Axial ratings of the ball part: dynamic Ca 7.74 kN (Ca), static C0a 13.7 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5910",
      "NKIA 5910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5910",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5910",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 47.3,
    "static_load_kN": 85,
    "fatigue_load_limit_kN": 10.6,
    "max_rpm": 8000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8000,
    "weight_g": 390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5910 is the combined needle roller / three-point contact ball bearings entry for a 50 mm shaft: needle rollers run the radial load while the three-point contact ball set takes axial force in both directions through the three-point contact geometry, in a single machined envelope of 50×72×34 mm. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 595910 the heavy 59 dimension series around the 50 mm bore. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Speed ceilings differ by part: 7,000 r/min thermal reference and 8,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 47.3/85 kN ratings are SKF catalogue values for this exact execution (NKIB 5910); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5910 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 47.3/85 kN ratings and 390 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKIB 5910?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIB 5910 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIB 5910 have?",
        "a": "A NKIB 5910 measures 50 mm bore/Fw × 72 mm outside diameter × 34 mm width (1.969 × 2.835 × 1.339 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 47.3 kN, static C0 85 kN, fatigue limit Pu 10.6 kN, limiting speed 8,000 r/min, reference speed 7,000 r/min, mass about 390 g. Axial ratings of the ball part: dynamic Ca 7.74 kN (Ca), static C0a 13.7 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "What does NKIB 5910 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595910 gives the series and 50 mm bore. The offset (s 30 mm) positions the ball raceway inside the 34 mm overall width."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5910",
      "NKIB 5910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5911",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5911",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 57.2,
    "static_load_kN": 106,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5911 solves compact radial-plus-thrust duty: a needle roller cage and an angular contact ball bearing built into one 34 mm wide unit with a 55 mm bore and 80 mm outside diameter. In SKF nomenclature NKIA denotes the combined construction and 595911 the series/bore; the ball raceway sits offset on the inner ring, which is why the 34 mm overall width is greater than a plain needle bearing of the same bore. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 57.2 kN, radial C0 106 kN, axial dynamic 9.27 kN (Ca) and axial static 16.7 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: press on the inner ring faces only — the ball set offset (a catalogue-listed offset) makes the unit sensitive to bending; support both rings square to the 55 mm seat and never drive through the rolling elements.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "The quoted 57.2/106 kN ratings are SKF catalogue values for this exact execution (NKIA 5911); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 5911 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 57.2/106 kN ratings and 550 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKIA 5911 mean in SKF part numbering?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595911 gives the series and 55 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 34 mm overall width."
      },
      {
        "q": "Does the NKIA 5911 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIA 5911 rides directly on the 55 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIA 5911?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 55 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIA 5911 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5911",
      "NKIA 5911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5911",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5911",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 57.2,
    "static_load_kN": 106,
    "fatigue_load_limit_kN": 13.2,
    "max_rpm": 7000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7000,
    "weight_g": 560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5911 is a combined needle roller / three-point ball bearing: one unit carrying radial load on the needle roller set and one-direction-leaning axial load on the ball set, 55×80×38 mm, listed by SKF in SKF catalogue PUB BU/P1 17000. The NKIB 5911 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 55 mm; the 38 mm width covers both the roller cage and the offset ball set (s offset 34 mm). NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Selection arithmetic for the combined unit: radial C 57.2 kN, radial C0 106 kN, axial dynamic 9.27 kN (Ca) and axial static 16.7 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 55 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 55 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 57.2/106 kN ratings are SKF catalogue values for this exact execution (NKIB 5911); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 9.27 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5911 facing the working thrust.",
      "The 57.2/106 kN ratings and 560 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKIB 5911 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIB 5911 rides directly on the 55 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIB 5911 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 55 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIB 5911?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 55 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 12.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIB 5911?",
        "a": "A NKIB 5911 measures 55 mm bore/Fw × 80 mm outside diameter × 38 mm width (2.165 × 3.15 × 1.496 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 57.2 kN, static C0 106 kN, fatigue limit Pu 13.2 kN, limiting speed 7,000 r/min, reference speed 6,300 r/min, mass about 560 g. Axial ratings of the ball part: dynamic Ca 9.27 kN (Ca), static C0a 16.7 kN (C0a); three-point contact geometry accepts axial load in both directions."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5911",
      "NKIB 5911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5912",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5912",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 14.3,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 590,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIA 5912 among the combined needle roller / angular contact ball bearings: radial capacity from the needle roller set (60.5 kN C), axial capacity from the angular contact ball part 9.58 kN (Ca), all within a 85×34 mm outline. The designation NKIA 5912 identifies the two rolling elements in one unit; the 60 mm bore and 85 mm OD come from the 59-series plan, and the 34 mm width stacks roller set plus ball set. Execution notes: the ball set runs on a raceway offset by a catalogue-listed offset from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Speed ceilings differ by part: 6,000 r/min thermal reference and 6,700 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: press on the inner ring faces only — the ball set offset (a catalogue-listed offset) makes the unit sensitive to bending; support both rings square to the 60 mm seat and never drive through the rolling elements.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 60 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 60.5/114 kN ratings are SKF catalogue values for this exact execution (NKIA 5912); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 9.58 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIA 5912 facing the working thrust.",
      "The 60.5/114 kN ratings and 590 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKIA 5912?",
        "a": "A NKIA 5912 measures 60 mm bore/Fw × 85 mm outside diameter × 34 mm width (2.362 × 3.346 × 1.339 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 60.5 kN, static C0 114 kN, fatigue limit Pu 14.3 kN, limiting speed 6,700 r/min, reference speed 6,000 r/min, mass about 590 g. Axial ratings of the ball part: dynamic Ca 9.58 kN (Ca), static C0a 18 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "How is the NKIA 5912 designation read?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595912 gives the series and 60 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 34 mm overall width."
      },
      {
        "q": "Can the NKIA 5912 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIA 5912 rides directly on the 60 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIA 5912 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5912",
      "NKIA 5912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5912",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5912",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 14.3,
    "max_rpm": 6700,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 6700,
    "weight_g": 600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKIB 5912 designates a combined bearing of the combined needle roller / three-point contact ball bearings: caged needle rollers for the 60 mm radial seat share a shaft with an integral three-point contact ball set rated 9.58 kN (Ca) axially. In SKF nomenclature NKIB denotes the combined construction and 595912 the series/bore; the ball raceway sits offset on the inner ring, which is why the 38 mm overall width is greater than a plain needle bearing of the same bore. Execution notes: the ball set runs on a raceway offset by s 34 mm from the roller set centreline — this offset is why the overall width exceeds a plain needle bearing and why the units cannot be dismantled without losing preload. Speed ceilings differ by part: 6,000 r/min thermal reference and 6,700 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 60 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 9.58 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 60.5/114 kN ratings and 600 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKIB 5912 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595912 gives the series and 60 mm bore. The offset (s 34 mm) positions the ball raceway inside the 38 mm overall width."
      },
      {
        "q": "Does the NKIB 5912 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 5912 rides directly on the 60 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "What mounting mistakes ruin a NKIB 5912?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKIB 5912 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5912",
      "NKIB 5912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5913",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5913",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 61.6,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 14.6,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 640,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For shafts where a separate thrust bearing would lengthen the assembly, NKIA 5913 integrates needle rollers and an angular contact ball bearing: 65 mm bore, 90 mm OD, 34 mm overall width including the ball set offset. Reading the designation: the letters combine the needle roller family with the ball execution — NKIA marks angular contact — and 595913 the heavy 59 dimension series around the 65 mm bore. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Selection arithmetic for the combined unit: radial C 61.6 kN, radial C0 120 kN, axial dynamic 9.96 kN (Ca) and axial static 19.2 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: press on the inner ring faces only — the ball set offset (a catalogue-listed offset) makes the unit sensitive to bending; support both rings square to the 65 mm seat and never drive through the rolling elements.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 5,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 65 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 9.96 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 61.6/120 kN ratings and 640 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKIA 5913 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIA 5913 have?",
        "a": "A NKIA 5913 measures 65 mm bore/Fw × 90 mm outside diameter × 34 mm width (2.559 × 3.543 × 1.339 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 61.6 kN, static C0 120 kN, fatigue limit Pu 14.6 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 640 g. Axial ratings of the ball part: dynamic Ca 9.96 kN (Ca), static C0a 19.2 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "What does NKIA 5913 mean in SKF part numbering?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595913 gives the series and 65 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 34 mm overall width."
      },
      {
        "q": "Does the NKIA 5913 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIA 5913 rides directly on the 65 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5913",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5913",
      "NKIA 5913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5913",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5913",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 61.6,
    "static_load_kN": 120,
    "fatigue_load_limit_kN": 14.6,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 640,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIB 5913 solves compact radial-plus-thrust duty: a needle roller cage and an three-point contact ball bearing built into one 38 mm wide unit with a 65 mm bore and 90 mm outside diameter. The designation NKIB 5913 identifies the two rolling elements in one unit; the 65 mm bore and 90 mm OD come from the 59-series plan, and the 38 mm width stacks roller set plus ball set. The combined unit is greased for life at assembly in many applications; relubrication, where provided, must reach both the roller cage and the ball set through the same axial bore features. Selection arithmetic for the combined unit: radial C 61.6 kN, radial C0 120 kN, axial dynamic 9.96 kN (Ca) and axial static 19.2 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 65 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NKIB 5913 shares its 65×90×38 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 61.6/120 kN ratings and 640 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKIB 5913?",
        "a": "A NKIB 5913 measures 65 mm bore/Fw × 90 mm outside diameter × 38 mm width (2.559 × 3.543 × 1.496 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 61.6 kN, static C0 120 kN, fatigue limit Pu 14.6 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 640 g. Axial ratings of the ball part: dynamic Ca 9.96 kN (Ca), static C0a 19.2 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "How is the NKIB 5913 designation read?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595913 gives the series and 65 mm bore. The offset (s 34 mm) positions the ball raceway inside the 38 mm overall width."
      },
      {
        "q": "Can the NKIB 5913 run on an unhardened shaft?",
        "a": "The needle roller part of the NKIB 5913 rides directly on the 65 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      },
      {
        "q": "How should the NKIB 5913 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 65 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5913",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5913",
      "NKIB 5913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIA5914",
    "brand": "SKF",
    "manufacturer_designation": "NKIA 5914",
    "series": "NKIA-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 100,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 84.2,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 20.8,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 980,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKIA 5914 is the combined needle roller / angular contact ball bearings entry for a 70 mm shaft: needle rollers run the radial load while the angular contact ball set takes axial force primarily in one direction, in a single machined envelope of 70×100×40 mm. The NKIA 5914 code breaks into series letters (needle roller + ball), dimension series 59, and the two-digit bore reference for 70 mm; the 40 mm width covers both the roller cage and the offset ball set (offset per catalogue s column). NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Speed ceilings differ by part: 5,000 r/min thermal reference and 5,600 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: press on the inner ring faces only — the ball set offset (a catalogue-listed offset) makes the unit sensitive to bending; support both rings square to the 70 mm seat and never drive through the rolling elements.",
    "applications": [
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions",
      "pump rotors with hydraulic axial pull",
      "bevel gear shafts with moderate axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Do not interchange envelope-identical needle families blindly: NKIA 5914 shares its 70×100×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 5,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the ball-raceway part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 84.2/163 kN ratings and 980 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKIA 5914 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 70 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKIA 5914?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 70 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 15.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKIA 5914?",
        "a": "A NKIA 5914 measures 70 mm bore/Fw × 100 mm outside diameter × 40 mm width (2.756 × 3.937 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 84.2 kN, static C0 163 kN, fatigue limit Pu 20.8 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 980 g. Axial ratings of the ball part: dynamic Ca 13.2 kN (Ca), static C0a 25 kN (C0a); angular contact geometry leans axial capacity toward one direction."
      },
      {
        "q": "How is the NKIA 5914 designation read?",
        "a": "NKIA combines a needle roller cage with an angular contact ball bearing in one unit; 595914 gives the series and 70 mm bore. The offset (a catalogue-listed offset) positions the ball raceway inside the 40 mm overall width."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIA5914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIA5914",
      "NKIA 5914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKIB5914",
    "brand": "SKF",
    "manufacturer_designation": "NKIB 5914",
    "series": "NKIB-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 100,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 84.2,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 20.8,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKIB 5914 among the combined needle roller / three-point contact ball bearings: radial capacity from the needle roller set (84.2 kN C), axial capacity from the three-point contact ball part 13.2 kN (Ca), all within a 100×45 mm outline. Reading the designation: the letters combine the needle roller family with the ball execution — NKIB marks three-point contact — and 595914 the heavy 59 dimension series around the 70 mm bore. NKIB three-point contact ball raceways accept axial load in both directions, while NKIA angular contact ball raceways lean the axial capacity toward one direction — check the load direction before ordering either. Speed ceilings differ by part: 5,000 r/min thermal reference and 5,600 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit the combined unit so the ball raceway offset faces the working axial load, check rotation in both directions, and preload if required with the washer stack the catalogue recommends.",
    "applications": [
      "gearbox main shafts carrying radial plus one-direction thrust",
      "worm gear shafts with axial reaction toward the worm",
      "spindle heads needing compact radial-plus-axial support",
      "lead-screw and ball-screw support positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKIB 5914 shares its 70×100×45 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKIB 5914 facing the working thrust.",
      "Minimum axial load is a real requirement: below the catalogue minimum the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 84.2/163 kN ratings and 990 g mass are SKF catalogue values transcribed from ch. 7.7 of PUB BU/P1 17000 (PDF table page 654); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKIB 5914 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKIB 5914 have?",
        "a": "A NKIB 5914 measures 70 mm bore/Fw × 100 mm outside diameter × 45 mm width (2.756 × 3.937 × 1.772 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 84.2 kN, static C0 163 kN, fatigue limit Pu 20.8 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 990 g. Axial ratings of the ball part: dynamic Ca 13.2 kN (Ca), static C0a 25 kN (C0a); three-point contact geometry accepts axial load in both directions."
      },
      {
        "q": "What does NKIB 5914 mean in SKF part numbering?",
        "a": "NKIB combines a needle roller cage with an three-point contact ball bearing in one unit; 595914 gives the series and 70 mm bore. The offset (s 40 mm) positions the ball raceway inside the 45 mm overall width."
      },
      {
        "q": "Does the NKIB 5914 need a hardened and ground shaft?",
        "a": "The needle roller part of the NKIB 5914 rides directly on the 70 mm journal, so it must be hardened to 58–64 HRC and ground; the ball set runs on its own integrated raceways. There is no inner-ring variant — harden the shaft or move to a separate bearing arrangement."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKIB5914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.7 needle roller / angular contact ball bearings",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKIB5914",
      "NKIB 5914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX7-ZTN",
    "brand": "SKF",
    "manufacturer_designation": "NX 7 ZTN",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 14,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.81,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.29,
    "max_rpm": 6000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 6000,
    "weight_g": 14,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NX 7 ZTN packs radial and thrust capacity into 7×14×18 mm: needle rollers caged around the shaft, thrust balls packed without a cage above them, axial dynamic rating 3.45 kN (Ca). Reading the designation: NX marks needle roller + full complement thrust ball, the number the 7 mm shaft seat; 14 mm OD and 18 mm overall height follow the series plan. Full complement thrust parts run slower than caged ones: observe the 6,000 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Selection arithmetic for the combined unit: radial C 2.81 kN, radial C0 2.75 kN, axial dynamic 3.45 kN (Ca) and axial static 5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. The full complement thrust set has no cage to retain the balls — hold them with grease during assembly and never rotate the shaft before the axial preload (at least factor A 0.00013) is applied.",
    "applications": [
      "small hoisting and winch drums",
      "actuator output shafts",
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the NX 7 ZTN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "The quoted 2.81/2.75 kN ratings are SKF catalogue values for this exact execution (NX 7 ZTN); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 3.45 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 2.81/2.75 kN ratings and 14 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NX 7 ZTN mean in SKF part numbering?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 7 mm shaft; the catalogue plan completes 14 mm OD and 18 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Does the NX 7 ZTN need a hardened and ground shaft?",
        "a": "The radial needle part of the NX 7 ZTN runs directly on the 7 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NX 7 ZTN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 7 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NX 7 ZTN sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX7-TN",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 7×14×18 mm envelope and equivalent catalogue ratings; NX7-TN is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX7-ZTN",
      "NX 7 ZTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX7-TN",
    "brand": "SKF",
    "manufacturer_designation": "NX 7 TN",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 7,
    "D_mm": 14,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 2.81,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.29,
    "max_rpm": 11000,
    "reference_speed_rpm": 10000,
    "limiting_speed_rpm": 11000,
    "weight_g": 14,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NX 7 TN packs radial and thrust capacity into 7×14×18 mm: needle rollers caged around the shaft, thrust balls packed without a cage above them, axial dynamic rating 3.45 kN (Ca). The number in NX 7 TN is the shaft diameter in millimetres; NX types differ from NKX only in the thrust part — full complement balls here, caged balls there — which changes axial capacity and speed ceiling. The thrust washer set is keyed to the housing, the ball complement to the shaft washer — assembly orientation matters, since reverse axial shocks would unload the packed ball set. Selection arithmetic for the combined unit: radial C 2.81 kN, radial C0 2.75 kN, axial dynamic 3.45 kN (Ca) and axial static 5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Check after fitting that the radial needle cage and the thrust part rotate independently where the design allows; binding between the two indicates a bent washer or a stray ball.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At Fw 7 mm the rolling elements are under two millimetres long — handle the NX 7 TN like a watch part: one dropped assembly, one over-pressed cup or one coarse journal finish outweighs any catalogue rating difference.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Minimum axial load is a real requirement: below factor A 0.00013 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 2.81/2.75 kN ratings and 14 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NX 7 TN designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 7 mm shaft; the catalogue plan completes 14 mm OD and 18 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Can the NX 7 TN run on an unhardened shaft?",
        "a": "The radial needle part of the NX 7 TN runs directly on the 7 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NX 7 TN be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 7 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 7 TN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 7 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 3.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX7-ZTN",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 7×14×18 mm envelope and equivalent catalogue ratings; NX7-ZTN is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX7-TN",
      "NX 7 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX10-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 10 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 4.95,
    "static_load_kN": 4.55,
    "fatigue_load_limit_kN": 0.53,
    "max_rpm": 5600,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 5600,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NX 10 Z is a combined needle roller / full complement thrust ball bearing: a caged needle roller set for the 10 mm radial seat stacked with a maximum-ball-count thrust ball set, per SKF catalogue PUB BU/P1 17000 ch. 7.8. Reading the designation: NX marks needle roller + full complement thrust ball, the number the 10 mm shaft seat; 19 mm OD and 18 mm overall height follow the series plan. Full complement thrust parts run slower than caged ones: observe the 5,600 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Speed ceilings differ by part: 8,500 r/min thermal reference and 5,600 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. The full complement thrust set has no cage to retain the balls — hold them with grease during assembly and never rotate the shaft before the axial preload (at least factor A 0.00038) is applied.",
    "applications": [
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload",
      "small hoisting and winch drums",
      "actuator output shafts"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 8,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 10 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 10 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.00038 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 4.95/4.55 kN ratings and 25 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NX 10 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 10 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NX 10 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NX 10 Z have?",
        "a": "A NX 10 Z measures 10 mm bore/Fw × 19 mm outside diameter × 18 mm width (0.394 × 0.748 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.95 kN, static C0 4.55 kN, fatigue limit Pu 0.53 kN, limiting speed 5,600 r/min, reference speed 8,500 r/min, mass about 25 g. Axial ratings of the thrust part: dynamic Ca 5.07 kN (Ca), static C0a 8.5 kN (C0a), minimum load factor A 0.00038; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NX 10 Z mean in SKF part numbering?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 10 mm shaft; the catalogue plan completes 19 mm OD and 18 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX10",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×19×18 mm envelope and equivalent catalogue ratings; NX10 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX10-Z",
      "NX 10 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX10",
    "brand": "SKF",
    "manufacturer_designation": "NX 10",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 4.95,
    "static_load_kN": 4.55,
    "fatigue_load_limit_kN": 0.53,
    "max_rpm": 9500,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 9500,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where a 10 mm shaft needs radial support plus one-direction axial location in minimal length, NX 10 from the combined needle roller / full complement thrust ball bearings stacks both functions: 19 mm OD, thrust part 5.07 kN (Ca) dynamic. In SKF nomenclature the X in NX flags the combined radial-plus-thrust construction; the figure 10 selects the size, and the catalogue adds the 19 mm envelope and 18 mm height. Full complement thrust parts run slower than caged ones: observe the 9,500 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Selection arithmetic for the combined unit: radial C 4.95 kN, radial C0 4.55 kN, axial dynamic 5.07 kN (Ca) and axial static 8.5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 8,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 10 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 10 facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.00038 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 4.95/4.55 kN ratings and 25 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NX 10 have?",
        "a": "A NX 10 measures 10 mm bore/Fw × 19 mm outside diameter × 18 mm width (0.394 × 0.748 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 4.95 kN, static C0 4.55 kN, fatigue limit Pu 0.53 kN, limiting speed 9,500 r/min, reference speed 8,500 r/min, mass about 25 g. Axial ratings of the thrust part: dynamic Ca 5.07 kN (Ca), static C0a 8.5 kN (C0a), minimum load factor A 0.00038; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NX 10 mean in SKF part numbering?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 10 mm shaft; the catalogue plan completes 19 mm OD and 18 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Does the NX 10 need a hardened and ground shaft?",
        "a": "The radial needle part of the NX 10 runs directly on the 10 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NX 10?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 10 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX10-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×19×18 mm envelope and equivalent catalogue ratings; NX10-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX10",
      "NX 10"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX12-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 12 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 5.39,
    "static_load_kN": 5.2,
    "fatigue_load_limit_kN": 0.61,
    "max_rpm": 5300,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 5300,
    "weight_g": 28,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NX 12 Z is a combined needle roller / full complement thrust ball bearing: a caged needle roller set for the 12 mm radial seat stacked with a maximum-ball-count thrust ball set, per SKF catalogue PUB BU/P1 17000 ch. 7.8. The number in NX 12 Z is the shaft diameter in millimetres; NX types differ from NKX only in the thrust part — full complement balls here, caged balls there — which changes axial capacity and speed ceiling. Full complement thrust parts run slower than caged ones: observe the 5,300 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. The full complement thrust set has no cage to retain the balls — hold them with grease during assembly and never rotate the shaft before the axial preload (at least factor A 0.00048) is applied.",
    "applications": [
      "actuator output shafts",
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 12 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.00048 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 5.39/5.2 kN ratings and 28 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NX 12 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 12 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 12 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 12 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 12 Z?",
        "a": "A NX 12 Z measures 12 mm bore/Fw × 21 mm outside diameter × 18 mm width (0.472 × 0.827 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.39 kN, static C0 5.2 kN, fatigue limit Pu 0.61 kN, limiting speed 5,300 r/min, reference speed 8,000 r/min, mass about 28 g. Axial ratings of the thrust part: dynamic Ca 5.27 kN (Ca), static C0a 9.65 kN (C0a), minimum load factor A 0.00048; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 12 Z designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 12 mm shaft; the catalogue plan completes 21 mm OD and 18 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX12",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×21×18 mm envelope and equivalent catalogue ratings; NX12 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX12-Z",
      "NX 12 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX12",
    "brand": "SKF",
    "manufacturer_designation": "NX 12",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 5.39,
    "static_load_kN": 5.2,
    "fatigue_load_limit_kN": 0.61,
    "max_rpm": 9000,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 9000,
    "weight_g": 28,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / full complement thrust ball bearings execution NX 12 measures 12×21×18 mm: radial duty on caged needle rollers, axial duty on a full complement of thrust balls rated 5.27 kN (Ca), both in one shaft position. Reading the designation: NX marks needle roller + full complement thrust ball, the number the 12 mm shaft seat; 21 mm OD and 18 mm overall height follow the series plan. The thrust washer set is keyed to the housing, the ball complement to the shaft washer — assembly orientation matters, since reverse axial shocks would unload the packed ball set. Selection arithmetic for the combined unit: radial C 5.39 kN, radial C0 5.2 kN, axial dynamic 5.27 kN (Ca) and axial static 9.65 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NX 12 shares its 12×21×18 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 5.27 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 5.39/5.2 kN ratings and 28 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NX 12?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 12 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NX 12 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NX 12 have?",
        "a": "A NX 12 measures 12 mm bore/Fw × 21 mm outside diameter × 18 mm width (0.472 × 0.827 × 0.709 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.39 kN, static C0 5.2 kN, fatigue limit Pu 0.61 kN, limiting speed 9,000 r/min, reference speed 8,000 r/min, mass about 28 g. Axial ratings of the thrust part: dynamic Ca 5.27 kN (Ca), static C0a 9.65 kN (C0a), minimum load factor A 0.00048; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NX 12 mean in SKF part numbering?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 12 mm shaft; the catalogue plan completes 21 mm OD and 18 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX12-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×21×18 mm envelope and equivalent catalogue ratings; NX12-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX12",
      "NX 12"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX15-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 15 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 5300,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 5300,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NX 15 Z denotes a combined bearing whose thrust part is filled with the maximum number of balls: highest axial capacity of the NX/NKX family at low-to-moderate speed, radial part 11 kN C. The number in NX 15 Z is the shaft diameter in millimetres; NX types differ from NKX only in the thrust part — full complement balls here, caged balls there — which changes axial capacity and speed ceiling. Full complement thrust parts run slower than caged ones: observe the 5,300 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Speed ceilings differ by part: 7,500 r/min thermal reference and 5,300 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload",
      "small hoisting and winch drums",
      "actuator output shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NX 15 Z shares its 15×24×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Do not treat the axial rating 6.18 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 15 Z facing the working thrust.",
      "The 11/14 kN ratings and 48 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NX 15 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 15 Z?",
        "a": "A NX 15 Z measures 15 mm bore/Fw × 24 mm outside diameter × 28 mm width (0.591 × 0.945 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11 kN, static C0 14 kN, fatigue limit Pu 1.66 kN, limiting speed 5,300 r/min, reference speed 7,500 r/min, mass about 48 g. Axial ratings of the thrust part: dynamic Ca 6.18 kN (Ca), static C0a 12.2 kN (C0a), minimum load factor A 0.00077; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 15 Z designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 15 mm shaft; the catalogue plan completes 24 mm OD and 28 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Can the NX 15 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NX 15 Z runs directly on the 15 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×24×28 mm envelope and equivalent catalogue ratings; NX15 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX15-Z",
      "NX 15 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX15",
    "brand": "SKF",
    "manufacturer_designation": "NX 15",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 8500,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 8500,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NX 15 for light, slow combined loads: the full complement thrust ball set gives the greatest axial capacity for the section, while the caged needle rollers take 11 kN radial. The number in NX 15 is the shaft diameter in millimetres; NX types differ from NKX only in the thrust part — full complement balls here, caged balls there — which changes axial capacity and speed ceiling. The thrust washer set is keyed to the housing, the ball complement to the shaft washer — assembly orientation matters, since reverse axial shocks would unload the packed ball set. Speed ceilings differ by part: 7,500 r/min thermal reference and 8,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 11/14 kN ratings are SKF catalogue values for this exact execution (NX 15); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 6.18 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 15 facing the working thrust.",
      "The 11/14 kN ratings and 48 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NX 15?",
        "a": "A NX 15 measures 15 mm bore/Fw × 24 mm outside diameter × 28 mm width (0.591 × 0.945 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11 kN, static C0 14 kN, fatigue limit Pu 1.66 kN, limiting speed 8,500 r/min, reference speed 7,500 r/min, mass about 48 g. Axial ratings of the thrust part: dynamic Ca 6.18 kN (Ca), static C0a 12.2 kN (C0a), minimum load factor A 0.00077; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 15 designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 15 mm shaft; the catalogue plan completes 24 mm OD and 28 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Can the NX 15 run on an unhardened shaft?",
        "a": "The radial needle part of the NX 15 runs directly on the 15 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NX 15 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×24×28 mm envelope and equivalent catalogue ratings; NX15-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX15",
      "NX 15"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX17-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 17 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 5000,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 5000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NX 17 Z denotes a combined bearing whose thrust part is filled with the maximum number of balls: highest axial capacity of the NX/NKX family at low-to-moderate speed, radial part 12.1 kN C. The NX 17 Z code gives only the 17 mm Fw — the construction is fixed by the letters: caged radial needles below, packed thrust balls above, 28 mm total height. Full complement thrust parts run slower than caged ones: observe the 5,000 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Selection arithmetic for the combined unit: radial C 12.1 kN, radial C0 16.6 kN, axial dynamic 6.37 kN (Ca) and axial static 13.4 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not treat the axial rating 6.37 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 17 Z facing the working thrust.",
      "The 12.1/16.6 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NX 17 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 17 Z?",
        "a": "A NX 17 Z measures 17 mm bore/Fw × 26 mm outside diameter × 28 mm width (0.669 × 1.024 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 5,000 r/min, reference speed 7,000 r/min, mass about 53 g. Axial ratings of the thrust part: dynamic Ca 6.37 kN (Ca), static C0a 13.4 kN (C0a), minimum load factor A 0.00093; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 17 Z designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 17 mm shaft; the catalogue plan completes 26 mm OD and 28 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Can the NX 17 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NX 17 Z runs directly on the 17 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×26×28 mm envelope and equivalent catalogue ratings; NX17 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX17-Z",
      "NX 17 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX17",
    "brand": "SKF",
    "manufacturer_designation": "NX 17",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 8500,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 8500,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NX 17 is a combined needle roller / full complement thrust ball bearing: a caged needle roller set for the 17 mm radial seat stacked with a maximum-ball-count thrust ball set, per SKF catalogue PUB BU/P1 17000 ch. 7.8. The NX 17 code gives only the 17 mm Fw — the construction is fixed by the letters: caged radial needles below, packed thrust balls above, 28 mm total height. Execution notes: the thrust part is filled with the maximum number of balls, giving the family's highest axial capacity, but the packed set needs a minimum axial load (factor A 0.00093) to keep every ball tracking its raceway. Speed ceilings differ by part: 7,000 r/min thermal reference and 8,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NX 17 shares its 17×26×28 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 7,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Minimum axial load is a real requirement: below factor A 0.00093 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 12.1/16.6 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NX 17 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 17?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 17?",
        "a": "A NX 17 measures 17 mm bore/Fw × 26 mm outside diameter × 28 mm width (0.669 × 1.024 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 8,500 r/min, reference speed 7,000 r/min, mass about 53 g. Axial ratings of the thrust part: dynamic Ca 6.37 kN (Ca), static C0a 13.4 kN (C0a), minimum load factor A 0.00093; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 17 designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 17 mm shaft; the catalogue plan completes 26 mm OD and 28 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×26×28 mm envelope and equivalent catalogue ratings; NX17-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX17",
      "NX 17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX20-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 20 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 30,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 19.3,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 4500,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 4500,
    "weight_g": 68,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where a 20 mm shaft needs radial support plus one-direction axial location in minimal length, NX 20 Z from the combined needle roller / full complement thrust ball bearings stacks both functions: 30 mm OD, thrust part 7.8 kN (Ca) dynamic. The NX 20 Z code gives only the 20 mm Fw — the construction is fixed by the letters: caged radial needles below, packed thrust balls above, 28 mm total height. Full complement thrust parts run slower than caged ones: observe the 4,500 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. The minimum load factor A 0.0016 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload",
      "small hoisting and winch drums"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 20 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 13.2/19.3 kN ratings are SKF catalogue values for this exact execution (NX 20 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 20 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.0016 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 13.2/19.3 kN ratings and 68 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NX 20 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 20 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 20 Z?",
        "a": "A NX 20 Z measures 20 mm bore/Fw × 30 mm outside diameter × 28 mm width (0.787 × 1.181 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.2 kN, static C0 19.3 kN, fatigue limit Pu 2.28 kN, limiting speed 4,500 r/min, reference speed 6,300 r/min, mass about 68 g. Axial ratings of the thrust part: dynamic Ca 7.8 kN (Ca), static C0a 17.3 kN (C0a), minimum load factor A 0.0016; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 20 Z designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 20 mm shaft; the catalogue plan completes 30 mm OD and 28 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×30×28 mm envelope and equivalent catalogue ratings; NX20 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX20-Z",
      "NX 20 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX20",
    "brand": "SKF",
    "manufacturer_designation": "NX 20",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 30,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 19.3,
    "fatigue_load_limit_kN": 2.28,
    "max_rpm": 7500,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 7500,
    "weight_g": 68,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NX 20 denotes a combined bearing whose thrust part is filled with the maximum number of balls: highest axial capacity of the NX/NKX family at low-to-moderate speed, radial part 13.2 kN C. The number in NX 20 is the shaft diameter in millimetres; NX types differ from NKX only in the thrust part — full complement balls here, caged balls there — which changes axial capacity and speed ceiling. Execution notes: the thrust part is filled with the maximum number of balls, giving the family's highest axial capacity, but the packed set needs a minimum axial load (factor A 0.0016) to keep every ball tracking its raceway. Speed ceilings differ by part: 6,300 r/min thermal reference and 7,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Check after fitting that the radial needle cage and the thrust part rotate independently where the design allows; binding between the two indicates a bent washer or a stray ball.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 20 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 13.2/19.3 kN ratings are SKF catalogue values for this exact execution (NX 20); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 7.8 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 20 facing the working thrust.",
      "The 13.2/19.3 kN ratings and 68 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NX 20 run on an unhardened shaft?",
        "a": "The radial needle part of the NX 20 runs directly on the 20 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NX 20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 20?",
        "a": "A NX 20 measures 20 mm bore/Fw × 30 mm outside diameter × 28 mm width (0.787 × 1.181 × 1.102 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 13.2 kN, static C0 19.3 kN, fatigue limit Pu 2.28 kN, limiting speed 7,500 r/min, reference speed 6,300 r/min, mass about 68 g. Axial ratings of the thrust part: dynamic Ca 7.8 kN (Ca), static C0a 17.3 kN (C0a), minimum load factor A 0.0016; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×30×28 mm envelope and equivalent catalogue ratings; NX20-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX20",
      "NX 20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX25-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 25 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 2.9,
    "max_rpm": 3800,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 3800,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NX 25 Z denotes a combined bearing whose thrust part is filled with the maximum number of balls: highest axial capacity of the NX/NKX family at low-to-moderate speed, radial part 15.1 kN C. The number in NX 25 Z is the shaft diameter in millimetres; NX types differ from NKX only in the thrust part — full complement balls here, caged balls there — which changes axial capacity and speed ceiling. Full complement thrust parts run slower than caged ones: observe the 3,800 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. The minimum load factor A 0.0042 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload",
      "small hoisting and winch drums"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 15.1/24.5 kN ratings are SKF catalogue values for this exact execution (NX 25 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 12.4 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 15.1/24.5 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NX 25 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 25 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 25 Z?",
        "a": "A NX 25 Z measures 25 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.984 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 24.5 kN, fatigue limit Pu 2.9 kN, limiting speed 3,800 r/min, reference speed 5,600 r/min, mass about 120 g. Axial ratings of the thrust part: dynamic Ca 12.4 kN (Ca), static C0a 28.5 kN (C0a), minimum load factor A 0.0042; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 25 Z designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 25 mm shaft; the catalogue plan completes 37 mm OD and 30 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×37×30 mm envelope and equivalent catalogue ratings; NX25 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 35.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX25-Z",
      "NX 25 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX25",
    "brand": "SKF",
    "manufacturer_designation": "NX 25",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 15.1,
    "static_load_kN": 24.5,
    "fatigue_load_limit_kN": 2.9,
    "max_rpm": 6300,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 6300,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / full complement thrust ball bearings execution NX 25 measures 25×37×30 mm: radial duty on caged needle rollers, axial duty on a full complement of thrust balls rated 12.4 kN (Ca), both in one shaft position. Reading the designation: NX marks needle roller + full complement thrust ball, the number the 25 mm shaft seat; 37 mm OD and 30 mm overall height follow the series plan. Full complement thrust parts run slower than caged ones: observe the 6,300 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Selection arithmetic for the combined unit: radial C 15.1 kN, radial C0 24.5 kN, axial dynamic 12.4 kN (Ca) and axial static 28.5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Check after fitting that the radial needle cage and the thrust part rotate independently where the design allows; binding between the two indicates a bent washer or a stray ball.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 15.1/24.5 kN ratings are SKF catalogue values for this exact execution (NX 25); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 12.4 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 15.1/24.5 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NX 25 need a hardened and ground shaft?",
        "a": "The radial needle part of the NX 25 runs directly on the 25 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NX 25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NX 25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NX 25 have?",
        "a": "A NX 25 measures 25 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.984 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 15.1 kN, static C0 24.5 kN, fatigue limit Pu 2.9 kN, limiting speed 6,300 r/min, reference speed 5,600 r/min, mass about 120 g. Axial ratings of the thrust part: dynamic Ca 12.4 kN (Ca), static C0a 28.5 kN (C0a), minimum load factor A 0.0042; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×37×30 mm envelope and equivalent catalogue ratings; NX25-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 35.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (15.1/24.5 vs 19/32.5 kN) — boundary dimensions match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX25",
      "NX 25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX30-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 30 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 3600,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 3600,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where a 30 mm shaft needs radial support plus one-direction axial location in minimal length, NX 30 Z from the combined needle roller / full complement thrust ball bearings stacks both functions: 42 mm OD, thrust part 12.7 kN (Ca) dynamic. The NX 30 Z code gives only the 30 mm Fw — the construction is fixed by the letters: caged radial needles below, packed thrust balls above, 30 mm total height. Full complement thrust parts run slower than caged ones: observe the 3,600 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Selection arithmetic for the combined unit: radial C 22.9 kN, radial C0 38 kN, axial dynamic 12.7 kN (Ca) and axial static 32.5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: assemble the thrust washer set with the keyed washer in the housing, fill the packed ball complement with grease so the balls adhere during fitting, and orient the thrust part toward the working axial load.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not treat the axial rating 12.7 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NX 30 Z facing the working thrust.",
      "The 22.9/38 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NX 30 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NX 30 Z runs directly on the 30 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NX 30 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NX 30 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 30 Z?",
        "a": "A NX 30 Z measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 3,600 r/min, reference speed 5,300 r/min, mass about 130 g. Axial ratings of the thrust part: dynamic Ca 12.7 kN (Ca), static C0a 32.5 kN (C0a), minimum load factor A 0.0055; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×42×30 mm envelope and equivalent catalogue ratings; NX30 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (22.9/38 vs 38/62 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX30-Z",
      "NX 30 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX30",
    "brand": "SKF",
    "manufacturer_designation": "NX 30",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 6000,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 6000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "Where a 30 mm shaft needs radial support plus one-direction axial location in minimal length, NX 30 from the combined needle roller / full complement thrust ball bearings stacks both functions: 42 mm OD, thrust part 12.7 kN (Ca) dynamic. Reading the designation: NX marks needle roller + full complement thrust ball, the number the 30 mm shaft seat; 42 mm OD and 30 mm overall height follow the series plan. The thrust washer set is keyed to the housing, the ball complement to the shaft washer — assembly orientation matters, since reverse axial shocks would unload the packed ball set. Selection arithmetic for the combined unit: radial C 22.9 kN, radial C0 38 kN, axial dynamic 12.7 kN (Ca) and axial static 32.5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. The full complement thrust set has no cage to retain the balls — hold them with grease during assembly and never rotate the shaft before the axial preload (at least factor A 0.0055) is applied.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 22.9/38 kN ratings are SKF catalogue values for this exact execution (NX 30); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 12.7 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 22.9/38 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NX 30 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NX 30 have?",
        "a": "A NX 30 measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 6,000 r/min, reference speed 5,300 r/min, mass about 130 g. Axial ratings of the thrust part: dynamic Ca 12.7 kN (Ca), static C0a 32.5 kN (C0a), minimum load factor A 0.0055; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NX 30 mean in SKF part numbering?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 30 mm shaft; the catalogue plan completes 42 mm OD and 30 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Does the NX 30 need a hardened and ground shaft?",
        "a": "The radial needle part of the NX 30 runs directly on the 30 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×42×30 mm envelope and equivalent catalogue ratings; NX30-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (22.9/38 vs 38/62 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX30",
      "NX 30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX35-Z",
    "brand": "SKF",
    "manufacturer_designation": "NX 35 Z",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 3400,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 3400,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / full complement thrust ball bearings execution NX 35 Z measures 35×47×30 mm: radial duty on caged needle rollers, axial duty on a full complement of thrust balls rated 13.5 kN (Ca), both in one shaft position. Reading the designation: NX marks needle roller + full complement thrust ball, the number the 35 mm shaft seat; 47 mm OD and 30 mm overall height follow the series plan. Full complement thrust parts run slower than caged ones: observe the 3,400 r/min limiting speed, and expect the thrust part to govern the thermal ceiling. Selection arithmetic for the combined unit: radial C 24.6 kN, radial C0 45 kN, axial dynamic 13.5 kN (Ca) and axial static 38 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Check after fitting that the radial needle cage and the thrust part rotate independently where the design allows; binding between the two indicates a bent washer or a stray ball.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 24.6/45 kN ratings are SKF catalogue values for this exact execution (NX 35 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 13.5 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 24.6/45 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NX 35 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NX 35 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NX 35 Z have?",
        "a": "A NX 35 Z measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 3,400 r/min, reference speed 5,000 r/min, mass about 160 g. Axial ratings of the thrust part: dynamic Ca 13.5 kN (Ca), static C0a 38 kN (C0a), minimum load factor A 0.0075; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NX 35 Z mean in SKF part numbering?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 35 mm shaft; the catalogue plan completes 47 mm OD and 30 mm overall height. The packed thrust set maximises axial capacity at low speed."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×47×30 mm envelope and equivalent catalogue ratings; NX35 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (24.6/45 vs 42.9/75 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX35-Z",
      "NX 35 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NX35",
    "brand": "SKF",
    "manufacturer_designation": "NX 35",
    "series": "NX-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 5600,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 5600,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NX 35 for light, slow combined loads: the full complement thrust ball set gives the greatest axial capacity for the section, while the caged needle rollers take 24.6 kN radial. The NX 35 code gives only the 35 mm Fw — the construction is fixed by the letters: caged radial needles below, packed thrust balls above, 30 mm total height. Execution notes: the thrust part is filled with the maximum number of balls, giving the family's highest axial capacity, but the packed set needs a minimum axial load (factor A 0.0075) to keep every ball tracking its raceway. Speed ceilings differ by part: 5,000 r/min thermal reference and 5,600 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. The full complement thrust set has no cage to retain the balls — hold them with grease during assembly and never rotate the shaft before the axial preload (at least factor A 0.0075) is applied.",
    "applications": [
      "screw jack and lifting screw spindles",
      "valve and dosing pump stems with slow axial push",
      "light rotary tables under axial load",
      "oscillating pivots with steady axial preload"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Minimum axial load is a real requirement: below factor A 0.0075 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 24.6/45 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.8 of PUB BU/P1 17000 (PDF table page 656); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NX 35?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NX 35?",
        "a": "A NX 35 measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 5,600 r/min, reference speed 5,000 r/min, mass about 160 g. Axial ratings of the thrust part: dynamic Ca 13.5 kN (Ca), static C0a 38 kN (C0a), minimum load factor A 0.0075; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NX 35 designation read?",
        "a": "NX = needle roller radial part + full complement thrust ball part for a 35 mm shaft; the catalogue plan completes 47 mm OD and 30 mm overall height. The packed thrust set maximises axial capacity at low speed."
      },
      {
        "q": "Can the NX 35 run on an unhardened shaft?",
        "a": "The radial needle part of the NX 35 runs directly on the 35 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×47×30 mm envelope and equivalent catalogue ratings; NX35-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (24.6/45 vs 42.9/75 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.8 needle roller / thrust ball, full complement thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NX35",
      "NX 35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX10-ZTN",
    "brand": "SKF",
    "manufacturer_designation": "NKX 10 ZTN",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.94,
    "static_load_kN": 8,
    "fatigue_load_limit_kN": 0.9,
    "max_rpm": 8000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 8000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / thrust ball bearings with caged thrust part execution NKX 10 ZTN measures 10×19×23 mm and carries radial load 5.94 kN dynamic plus one-direction axial load 9.95 kN (Ca) — the caged thrust part runs at higher speed than full complement NX types. The code NKX 10 ZTN reads as combined radial/thrust for a 10 mm shaft; the catalogue height 23 mm stacks the radial cage and the thrust set, and the 19 mm OD seats both parts in one bore. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Speed ceilings differ by part: 9,500 r/min thermal reference and 8,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not treat the axial rating 9.95 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 10 ZTN facing the working thrust.",
      "The 5.94/8 kN ratings and 36 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKX 10 ZTN?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 10 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 10 ZTN?",
        "a": "A NKX 10 ZTN measures 10 mm bore/Fw × 19 mm outside diameter × 23 mm width (0.394 × 0.748 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.94 kN, static C0 8 kN, fatigue limit Pu 0.9 kN, limiting speed 8,000 r/min, reference speed 9,500 r/min, mass about 36 g. Axial ratings of the thrust part: dynamic Ca 9.95 kN (Ca), static C0a 15.3 kN (C0a), minimum load factor A 0.0012; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 10 ZTN designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 10 mm shaft: 19 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 10 ZTN run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 10 ZTN runs directly on the 10 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX10-TN",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×19×23 mm envelope and equivalent catalogue ratings; NKX10-TN is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX10-ZTN",
      "NKX 10 ZTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX10-TN",
    "brand": "SKF",
    "manufacturer_designation": "NKX 10 TN",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 5.94,
    "static_load_kN": 8,
    "fatigue_load_limit_kN": 0.9,
    "max_rpm": 13000,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 13000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies NKX 10 TN for combined-load positions at moderate speed: the caged thrust balls reduce friction and allow 9,500 r/min reference where a full complement NX would overheat. In SKF nomenclature NKX is the combined family: the number states 10 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load",
      "conveyor screw thrust ends"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 10 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 19 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKX 10 TN shares its 10×19×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Do not treat the axial rating 9.95 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 10 TN facing the working thrust.",
      "The 5.94/8 kN ratings and 34 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKX 10 TN have?",
        "a": "A NKX 10 TN measures 10 mm bore/Fw × 19 mm outside diameter × 23 mm width (0.394 × 0.748 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 5.94 kN, static C0 8 kN, fatigue limit Pu 0.9 kN, limiting speed 13,000 r/min, reference speed 9,500 r/min, mass about 34 g. Axial ratings of the thrust part: dynamic Ca 9.95 kN (Ca), static C0a 15.3 kN (C0a), minimum load factor A 0.0012; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 10 TN mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 10 mm shaft: 19 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 10 TN need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 10 TN runs directly on the 10 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKX 10 TN?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 10 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX10-ZTN",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×19×23 mm envelope and equivalent catalogue ratings; NKX10-ZTN is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX10-TN",
      "NKX 10 TN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX12-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 12 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12,
    "fatigue_load_limit_kN": 1.43,
    "max_rpm": 7500,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 7500,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 12 Z integrates two bearings in one envelope: needle rollers for the radial load on a 12 mm seat, and a cage-held thrust ball set for axial loads up to 10.4 kN (Ca) dynamic. In SKF nomenclature NKX is the combined family: the number states 12 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. The minimum load factor A 0.0014 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 9.13/12 kN ratings are SKF catalogue values for this exact execution (NKX 12 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Minimum axial load is a real requirement: below factor A 0.0014 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 9.13/12 kN ratings and 40 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKX 12 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 12 Z have?",
        "a": "A NKX 12 Z measures 12 mm bore/Fw × 21 mm outside diameter × 23 mm width (0.472 × 0.827 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12 kN, fatigue limit Pu 1.43 kN, limiting speed 7,500 r/min, reference speed 9,000 r/min, mass about 40 g. Axial ratings of the thrust part: dynamic Ca 10.4 kN (Ca), static C0a 16.6 kN (C0a), minimum load factor A 0.0014; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 12 Z mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 12 mm shaft: 21 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 12 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 12 Z runs directly on the 12 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX12",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×21×23 mm envelope and equivalent catalogue ratings; NKX12 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX12-Z",
      "NKX 12 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX12",
    "brand": "SKF",
    "manufacturer_designation": "NKX 12",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 9.13,
    "static_load_kN": 12,
    "fatigue_load_limit_kN": 1.43,
    "max_rpm": 13000,
    "reference_speed_rpm": 9000,
    "limiting_speed_rpm": 13000,
    "weight_g": 38,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies NKX 12 for combined-load positions at moderate speed: the caged thrust balls reduce friction and allow 9,000 r/min reference where a full complement NX would overheat. Reading the designation: NKX marks needle roller + caged thrust ball, the number the 12 mm shaft seat; the 21 mm OD and 23 mm overall height come from the series plan. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 12 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 21 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 9.13/12 kN ratings are SKF catalogue values for this exact execution (NKX 12); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Minimum axial load is a real requirement: below factor A 0.0014 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 9.13/12 kN ratings and 38 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKX 12 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 12 have?",
        "a": "A NKX 12 measures 12 mm bore/Fw × 21 mm outside diameter × 23 mm width (0.472 × 0.827 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 9.13 kN, static C0 12 kN, fatigue limit Pu 1.43 kN, limiting speed 13,000 r/min, reference speed 9,000 r/min, mass about 38 g. Axial ratings of the thrust part: dynamic Ca 10.4 kN (Ca), static C0a 16.6 kN (C0a), minimum load factor A 0.0014; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 12 mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 12 mm shaft: 21 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 12 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 12 runs directly on the 12 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX12-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×21×23 mm envelope and equivalent catalogue ratings; NKX12-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX12",
      "NKX 12"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX15-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 15 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 7000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 7000,
    "weight_g": 47,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 15 Z is a combined needle roller / thrust ball bearing with a caged thrust part: radial load on caged needle rollers, axial load on a ball thrust set with stamped cages, per SKF catalogue PUB BU/P1 17000 ch. 7.9. In SKF nomenclature NKX is the combined family: the number states 15 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load",
      "conveyor screw thrust ends"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKX 15 Z shares its 15×24×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Do not treat the axial rating 10.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 15 Z facing the working thrust.",
      "The 11/14 kN ratings and 47 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKX 15 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 15 Z have?",
        "a": "A NKX 15 Z measures 15 mm bore/Fw × 24 mm outside diameter × 23 mm width (0.591 × 0.945 × 0.906 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 11 kN, static C0 14 kN, fatigue limit Pu 1.66 kN, limiting speed 7,000 r/min, reference speed 8,500 r/min, mass about 47 g. Axial ratings of the thrust part: dynamic Ca 10.6 kN (Ca), static C0a 18.3 kN (C0a), minimum load factor A 0.0017; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 15 Z mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 15 mm shaft: 24 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 15 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 15 Z runs directly on the 15 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×24×23 mm envelope and equivalent catalogue ratings; NKX15 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX15-Z",
      "NKX 15 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX15",
    "brand": "SKF",
    "manufacturer_designation": "NKX 15",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 12000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 12000,
    "weight_g": 44,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / thrust ball bearings with caged thrust part execution NKX 15 measures 15×24×23 mm and carries radial load 11 kN dynamic plus one-direction axial load 10.6 kN (Ca) — the caged thrust part runs at higher speed than full complement NX types. The code NKX 15 reads as combined radial/thrust for a 15 mm shaft; the catalogue height 23 mm stacks the radial cage and the thrust set, and the 24 mm OD seats both parts in one bore. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. The minimum load factor A 0.0017 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKX 15 shares its 15×24×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 8,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 10.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 11/14 kN ratings and 44 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKX 15 designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 15 mm shaft: 24 mm OD, 23 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 15 run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 15 runs directly on the 15 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKX 15 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 15?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×24×23 mm envelope and equivalent catalogue ratings; NKX15-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX15",
      "NKX 15"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX17-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 17 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 7000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 7000,
    "weight_g": 55,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 17 Z is a combined needle roller / thrust ball bearing with a caged thrust part: radial load on caged needle rollers, axial load on a ball thrust set with stamped cages, per SKF catalogue PUB BU/P1 17000 ch. 7.9. The NKX 17 Z figure gives the 17 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. The minimum load factor A 0.002 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Mounting: press the unit onto the 17 mm seat against the inner faces, orient the thrust set toward the axial load, and verify the 25 mm overall height against the housing stack after fitting.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 17 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 12.1/16.6 kN ratings are SKF catalogue values for this exact execution (NKX 17 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 17 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.002 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 12.1/16.6 kN ratings and 55 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKX 17 Z?",
        "a": "A NKX 17 Z measures 17 mm bore/Fw × 26 mm outside diameter × 25 mm width (0.669 × 1.024 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 7,000 r/min, reference speed 8,500 r/min, mass about 55 g. Axial ratings of the thrust part: dynamic Ca 10.8 kN (Ca), static C0a 19.6 kN (C0a), minimum load factor A 0.002; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 17 Z designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 17 mm shaft: 26 mm OD, 25 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 17 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 17 Z runs directly on the 17 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKX 17 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×26×25 mm envelope and equivalent catalogue ratings; NKX17 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX17-Z",
      "NKX 17 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX17",
    "brand": "SKF",
    "manufacturer_designation": "NKX 17",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 12000,
    "reference_speed_rpm": 8500,
    "limiting_speed_rpm": 12000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 17 integrates two bearings in one envelope: needle rollers for the radial load on a 17 mm seat, and a cage-held thrust ball set for axial loads up to 10.8 kN (Ca) dynamic. The NKX 17 figure gives the 17 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. Caged thrust balls allow higher speeds than the full complement NX execution in the same envelope; the trade-off is a somewhat lower axial rating — compare the Ca figures before choosing. The minimum load factor A 0.002 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 17 facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.002 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 12.1/16.6 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKX 17?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 17?",
        "a": "A NKX 17 measures 17 mm bore/Fw × 26 mm outside diameter × 25 mm width (0.669 × 1.024 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 12,000 r/min, reference speed 8,500 r/min, mass about 53 g. Axial ratings of the thrust part: dynamic Ca 10.8 kN (Ca), static C0a 19.6 kN (C0a), minimum load factor A 0.002; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 17 designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 17 mm shaft: 26 mm OD, 25 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 17 run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 17 runs directly on the 17 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×26×25 mm envelope and equivalent catalogue ratings; NKX17-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX17",
      "NKX 17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX20-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 20 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 30,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 6000,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 6000,
    "weight_g": 90,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 20 Z integrates two bearings in one envelope: needle rollers for the radial load on a 20 mm seat, and a cage-held thrust ball set for axial loads up to 14.3 kN (Ca) dynamic. Reading the designation: NKX marks needle roller + caged thrust ball, the number the 20 mm shaft seat; the 30 mm OD and 30 mm overall height come from the series plan. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Speed ceilings differ by part: 7,500 r/min thermal reference and 6,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 20 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 20 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.0038 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 16.5/25.5 kN ratings and 90 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKX 20 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKX 20 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 20 Z have?",
        "a": "A NKX 20 Z measures 20 mm bore/Fw × 30 mm outside diameter × 30 mm width (0.787 × 1.181 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.5 kN, static C0 25.5 kN, fatigue limit Pu 3.05 kN, limiting speed 6,000 r/min, reference speed 7,500 r/min, mass about 90 g. Axial ratings of the thrust part: dynamic Ca 14.3 kN (Ca), static C0a 27 kN (C0a), minimum load factor A 0.0038; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 20 Z mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 20 mm shaft: 30 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×30×30 mm envelope and equivalent catalogue ratings; NKX20 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX20-Z",
      "NKX 20 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX20",
    "brand": "SKF",
    "manufacturer_designation": "NKX 20",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 30,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 10000,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 10000,
    "weight_g": 83,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 20 mm shaft under radial plus one-direction axial load, NKX 20 from the combined needle roller / thrust ball bearings with caged thrust part provides both in 30×30 mm: needle roller cage below, caged thrust ball set above. The code NKX 20 reads as combined radial/thrust for a 20 mm shaft; the catalogue height 30 mm stacks the radial cage and the thrust set, and the 30 mm OD seats both parts in one bore. Caged thrust balls allow higher speeds than the full complement NX execution in the same envelope; the trade-off is a somewhat lower axial rating — compare the Ca figures before choosing. The minimum load factor A 0.0038 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Mounting: press the unit onto the 20 mm seat against the inner faces, orient the thrust set toward the axial load, and verify the 30 mm overall height against the housing stack after fitting.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKX 20 shares its 20×30×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 14.3 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 16.5/25.5 kN ratings and 83 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKX 20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 20?",
        "a": "A NKX 20 measures 20 mm bore/Fw × 30 mm outside diameter × 30 mm width (0.787 × 1.181 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.5 kN, static C0 25.5 kN, fatigue limit Pu 3.05 kN, limiting speed 10,000 r/min, reference speed 7,500 r/min, mass about 83 g. Axial ratings of the thrust part: dynamic Ca 14.3 kN (Ca), static C0a 27 kN (C0a), minimum load factor A 0.0038; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 20 designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 20 mm shaft: 30 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×30×30 mm envelope and equivalent catalogue ratings; NKX20-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX20",
      "NKX 20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX25-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 25 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 5500,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 5500,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 25 mm shaft under radial plus one-direction axial load, NKX 25 Z from the combined needle roller / thrust ball bearings with caged thrust part provides both in 37×30 mm: needle roller cage below, caged thrust ball set above. The code NKX 25 Z reads as combined radial/thrust for a 25 mm shaft; the catalogue height 30 mm stacks the radial cage and the thrust set, and the 37 mm OD seats both parts in one bore. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Speed ceilings differ by part: 6,300 r/min thermal reference and 5,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKX 25 Z shares its 25×37×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 6,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Do not treat the axial rating 19.5 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 25 Z facing the working thrust.",
      "The 19/32.5 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKX 25 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 25 Z?",
        "a": "A NKX 25 Z measures 25 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.984 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 5,500 r/min, reference speed 6,300 r/min, mass about 130 g. Axial ratings of the thrust part: dynamic Ca 19.5 kN (Ca), static C0a 40.5 kN (C0a), minimum load factor A 0.0085; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 25 Z designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 25 mm shaft: 37 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 25 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 25 Z runs directly on the 25 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×37×30 mm envelope and equivalent catalogue ratings; NKX25 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 35.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX25-Z",
      "NKX 25 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX25",
    "brand": "SKF",
    "manufacturer_designation": "NKX 25",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 9000,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 9000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies NKX 25 for combined-load positions at moderate speed: the caged thrust balls reduce friction and allow 6,300 r/min reference where a full complement NX would overheat. Reading the designation: NKX marks needle roller + caged thrust ball, the number the 25 mm shaft seat; the 37 mm OD and 30 mm overall height come from the series plan. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. Mounting: press the unit onto the 25 mm seat against the inner faces, orient the thrust set toward the axial load, and verify the 30 mm overall height against the housing stack after fitting.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 6,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Minimum axial load is a real requirement: below factor A 0.0085 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 19/32.5 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKX 25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKX 25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 25 have?",
        "a": "A NKX 25 measures 25 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.984 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 9,000 r/min, reference speed 6,300 r/min, mass about 130 g. Axial ratings of the thrust part: dynamic Ca 19.5 kN (Ca), static C0a 40.5 kN (C0a), minimum load factor A 0.0085; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 25 mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 25 mm shaft: 37 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×37×30 mm envelope and equivalent catalogue ratings; NKX25-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 35.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX25",
      "NKX 25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX30-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 30 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 5000,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 5000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKX 30 Z designates a combined bearing with needle roller radial part and caged thrust ball part: 30 mm shaft seat, 42 mm OD, thrust dynamic rating 20.3 kN (Ca). The NKX 30 Z figure gives the 30 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. The minimum load factor A 0.01 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 22.9/38 kN ratings are SKF catalogue values for this exact execution (NKX 30 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 30 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.01 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 22.9/38 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKX 30 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 30 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 30 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 30 Z?",
        "a": "A NKX 30 Z measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 5,000 r/min, reference speed 6,000 r/min, mass about 140 g. Axial ratings of the thrust part: dynamic Ca 20.3 kN (Ca), static C0a 45.5 kN (C0a), minimum load factor A 0.01; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 30 Z designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 30 mm shaft: 42 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×42×30 mm envelope and equivalent catalogue ratings; NKX30 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (22.9/38 vs 38/62 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX30-Z",
      "NKX 30 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX30",
    "brand": "SKF",
    "manufacturer_designation": "NKX 30",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 8500,
    "reference_speed_rpm": 6000,
    "limiting_speed_rpm": 8500,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKX 30 designates a combined bearing with needle roller radial part and caged thrust ball part: 30 mm shaft seat, 42 mm OD, thrust dynamic rating 20.3 kN (Ca). Reading the designation: NKX marks needle roller + caged thrust ball, the number the 30 mm shaft seat; the 42 mm OD and 30 mm overall height come from the series plan. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 6,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Minimum axial load is a real requirement: below factor A 0.01 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 22.9/38 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKX 30 have?",
        "a": "A NKX 30 measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 8,500 r/min, reference speed 6,000 r/min, mass about 140 g. Axial ratings of the thrust part: dynamic Ca 20.3 kN (Ca), static C0a 45.5 kN (C0a), minimum load factor A 0.01; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 30 mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 30 mm shaft: 42 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 30 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 30 runs directly on the 30 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKX 30?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×42×30 mm envelope and equivalent catalogue ratings; NKX30-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (22.9/38 vs 38/62 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX30",
      "NKX 30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX35-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 35 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 4500,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 4500,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 35 mm shaft under radial plus one-direction axial load, NKX 35 Z from the combined needle roller / thrust ball bearings with caged thrust part provides both in 47×30 mm: needle roller cage below, caged thrust ball set above. The code NKX 35 Z reads as combined radial/thrust for a 35 mm shaft; the catalogue height 30 mm stacks the radial cage and the thrust set, and the 47 mm OD seats both parts in one bore. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Speed ceilings differ by part: 5,600 r/min thermal reference and 4,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 24.6/45 kN ratings are SKF catalogue values for this exact execution (NKX 35 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 21.2 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 35 Z facing the working thrust.",
      "The 24.6/45 kN ratings and 170 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKX 35 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 35 Z?",
        "a": "A NKX 35 Z measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 4,500 r/min, reference speed 5,600 r/min, mass about 170 g. Axial ratings of the thrust part: dynamic Ca 21.2 kN (Ca), static C0a 51 kN (C0a), minimum load factor A 0.013; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 35 Z designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 35 mm shaft: 47 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 35 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 35 Z runs directly on the 35 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×47×30 mm envelope and equivalent catalogue ratings; NKX35 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (24.6/45 vs 42.9/75 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX35-Z",
      "NKX 35 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX35",
    "brand": "SKF",
    "manufacturer_designation": "NKX 35",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 7500,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 7500,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / thrust ball bearings with caged thrust part execution NKX 35 measures 35×47×30 mm and carries radial load 24.6 kN dynamic plus one-direction axial load 21.2 kN (Ca) — the caged thrust part runs at higher speed than full complement NX types. The NKX 35 figure gives the 35 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. Caged thrust balls allow higher speeds than the full complement NX execution in the same envelope; the trade-off is a somewhat lower axial rating — compare the Ca figures before choosing. The minimum load factor A 0.013 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 24.6/45 kN ratings are SKF catalogue values for this exact execution (NKX 35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 35 facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.013 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 24.6/45 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKX 35?",
        "a": "A NKX 35 measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 7,500 r/min, reference speed 5,600 r/min, mass about 160 g. Axial ratings of the thrust part: dynamic Ca 21.2 kN (Ca), static C0a 51 kN (C0a), minimum load factor A 0.013; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 35 designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 35 mm shaft: 47 mm OD, 30 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 35 run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 35 runs directly on the 35 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKX 35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×47×30 mm envelope and equivalent catalogue ratings; NKX35-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (24.6/45 vs 42.9/75 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX35",
      "NKX 35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX40-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 40 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 4000,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 4000,
    "weight_g": 210,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKX 40 Z designates a combined bearing with needle roller radial part and caged thrust ball part: 40 mm shaft seat, 52 mm OD, thrust dynamic rating 27 kN (Ca). The NKX 40 Z figure gives the 40 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. The minimum load factor A 0.024 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 40 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.024 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 26.4/51 kN ratings and 210 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKX 40 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 40 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 40 Z?",
        "a": "A NKX 40 Z measures 40 mm bore/Fw × 52 mm outside diameter × 32 mm width (1.575 × 2.047 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 4,000 r/min, reference speed 5,000 r/min, mass about 210 g. Axial ratings of the thrust part: dynamic Ca 27 kN (Ca), static C0a 68 kN (C0a), minimum load factor A 0.024; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKX 40 Z designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 40 mm shaft: 52 mm OD, 32 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX40",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×52×32 mm envelope and equivalent catalogue ratings; NKX40 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR40",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR40-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX40-Z",
      "NKX 40 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX40",
    "brand": "SKF",
    "manufacturer_designation": "NKX 40",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 7000,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 7000,
    "weight_g": 200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 40 mm shaft under radial plus one-direction axial load, NKX 40 from the combined needle roller / thrust ball bearings with caged thrust part provides both in 52×32 mm: needle roller cage below, caged thrust ball set above. The NKX 40 figure gives the 40 mm Fw; the letters fix the construction — radial needle cage plus thrust ball set with pressed cages — and the Z or TN suffix only modifies the thrust part. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. The minimum load factor A 0.024 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 26.4/51 kN ratings are SKF catalogue values for this exact execution (NKX 40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 40 facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.024 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 26.4/51 kN ratings and 200 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKX 40 run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 40 runs directly on the 40 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKX 40 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 40?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 40?",
        "a": "A NKX 40 measures 40 mm bore/Fw × 52 mm outside diameter × 32 mm width (1.575 × 2.047 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 7,000 r/min, reference speed 5,000 r/min, mass about 200 g. Axial ratings of the thrust part: dynamic Ca 27 kN (Ca), static C0a 68 kN (C0a), minimum load factor A 0.024; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX40-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×52×32 mm envelope and equivalent catalogue ratings; NKX40-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR40",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR40-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX40",
      "NKX 40"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX45-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 45 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 3800,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 3800,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies NKX 45 Z for combined-load positions at moderate speed: the caged thrust balls reduce friction and allow 4,500 r/min reference where a full complement NX would overheat. Reading the designation: NKX marks needle roller + caged thrust ball, the number the 45 mm shaft seat; the 58 mm OD and 32 mm overall height come from the series plan. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. The minimum load factor A 0.029 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 27.5/57 kN ratings are SKF catalogue values for this exact execution (NKX 45 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Do not treat the axial rating 28.1 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 45 Z facing the working thrust.",
      "The 27.5/57 kN ratings and 270 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKX 45 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 45 Z have?",
        "a": "A NKX 45 Z measures 45 mm bore/Fw × 58 mm outside diameter × 32 mm width (1.772 × 2.283 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 57 kN, fatigue limit Pu 7.1 kN, limiting speed 3,800 r/min, reference speed 4,500 r/min, mass about 270 g. Axial ratings of the thrust part: dynamic Ca 28.1 kN (Ca), static C0a 75 kN (C0a), minimum load factor A 0.029; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 45 Z mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 45 mm shaft: 58 mm OD, 32 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 45 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 45 Z runs directly on the 45 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX45",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×58×32 mm envelope and equivalent catalogue ratings; NKX45 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR45",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR45-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX45-Z",
      "NKX 45 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX45",
    "brand": "SKF",
    "manufacturer_designation": "NKX 45",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 6300,
    "reference_speed_rpm": 4500,
    "limiting_speed_rpm": 6300,
    "weight_g": 250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF supplies NKX 45 for combined-load positions at moderate speed: the caged thrust balls reduce friction and allow 4,500 r/min reference where a full complement NX would overheat. In SKF nomenclature NKX is the combined family: the number states 45 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 27.5/57 kN ratings are SKF catalogue values for this exact execution (NKX 45); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Do not treat the axial rating 28.1 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 45 facing the working thrust.",
      "The 27.5/57 kN ratings and 250 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKX 45 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 45 runs directly on the 45 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKX 45?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKX 45 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 45 have?",
        "a": "A NKX 45 measures 45 mm bore/Fw × 58 mm outside diameter × 32 mm width (1.772 × 2.283 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 57 kN, fatigue limit Pu 7.1 kN, limiting speed 6,300 r/min, reference speed 4,500 r/min, mass about 250 g. Axial ratings of the thrust part: dynamic Ca 28.1 kN (Ca), static C0a 75 kN (C0a), minimum load factor A 0.029; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX45-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×58×32 mm envelope and equivalent catalogue ratings; NKX45-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKXR45",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR45-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX45",
      "NKX 45"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX50-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 50 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 62,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 3600,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 3600,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / thrust ball bearings with caged thrust part execution NKX 50 Z measures 50×62×35 mm and carries radial load 38 kN dynamic plus one-direction axial load 28.6 kN (Ca) — the caged thrust part runs at higher speed than full complement NX types. In SKF nomenclature NKX is the combined family: the number states 50 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Selection arithmetic for the combined unit: radial C 38 kN, radial C0 78 kN, axial dynamic 28.6 kN (Ca) and axial static 81.5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "conveyor screw thrust ends",
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKX 50 Z shares its 50×62×35 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 50 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.034 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 38/78 kN ratings and 300 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKX 50 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKX 50 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 50 Z have?",
        "a": "A NKX 50 Z measures 50 mm bore/Fw × 62 mm outside diameter × 35 mm width (1.969 × 2.441 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 3,600 r/min, reference speed 4,300 r/min, mass about 300 g. Axial ratings of the thrust part: dynamic Ca 28.6 kN (Ca), static C0a 81.5 kN (C0a), minimum load factor A 0.034; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 50 Z mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 50 mm shaft: 62 mm OD, 35 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX50",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×62×35 mm envelope and equivalent catalogue ratings; NKX50 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NK50-35-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (38/78 vs 58.3/137 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR50",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR50-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX50-Z",
      "NKX 50 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX50",
    "brand": "SKF",
    "manufacturer_designation": "NKX 50",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 62,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 6300,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 6300,
    "weight_g": 280,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKX 50 designates a combined bearing with needle roller radial part and caged thrust ball part: 50 mm shaft seat, 62 mm OD, thrust dynamic rating 28.6 kN (Ca). In SKF nomenclature NKX is the combined family: the number states 50 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. Caged thrust balls allow higher speeds than the full complement NX execution in the same envelope; the trade-off is a somewhat lower axial rating — compare the Ca figures before choosing. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. Mounting: press the unit onto the 50 mm seat against the inner faces, orient the thrust set toward the axial load, and verify the 35 mm overall height against the housing stack after fitting.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 38/78 kN ratings are SKF catalogue values for this exact execution (NKX 50); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Do not treat the axial rating 28.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 50 facing the working thrust.",
      "The 38/78 kN ratings and 280 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKX 50 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 50 have?",
        "a": "A NKX 50 measures 50 mm bore/Fw × 62 mm outside diameter × 35 mm width (1.969 × 2.441 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 6,300 r/min, reference speed 4,300 r/min, mass about 280 g. Axial ratings of the thrust part: dynamic Ca 28.6 kN (Ca), static C0a 81.5 kN (C0a), minimum load factor A 0.034; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 50 mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 50 mm shaft: 62 mm OD, 35 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Does the NKX 50 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 50 runs directly on the 50 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX50-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×62×35 mm envelope and equivalent catalogue ratings; NKX50-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NK50-35-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (38/78 vs 58.3/137 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKXR50",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKXR50-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust needle execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX50",
      "NKX 50"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX60-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 60 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 72,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 41.8,
    "static_load_kN": 96.5,
    "fatigue_load_limit_kN": 11.8,
    "max_rpm": 3000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 3000,
    "weight_g": 380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 60 Z is a combined needle roller / thrust ball bearing with a caged thrust part: radial load on caged needle rollers, axial load on a ball thrust set with stamped cages, per SKF catalogue PUB BU/P1 17000 ch. 7.9. In SKF nomenclature NKX is the combined family: the number states 60 mm, and unlike NX the thrust balls are caged, trading some axial capacity for speed and friction. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "rotary indexing tables under combined load",
      "conveyor screw thrust ends",
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 60 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Do not treat the axial rating 41.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 60 Z facing the working thrust.",
      "The 41.8/96.5 kN ratings and 380 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKX 60 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKX 60 Z runs directly on the 60 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKX 60 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKX 60 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 60 Z have?",
        "a": "A NKX 60 Z measures 60 mm bore/Fw × 72 mm outside diameter × 40 mm width (2.362 × 2.835 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 41.8 kN, static C0 96.5 kN, fatigue limit Pu 11.8 kN, limiting speed 3,000 r/min, reference speed 3,600 r/min, mass about 380 g. Axial ratings of the thrust part: dynamic Ca 41.6 kN (Ca), static C0a 122 kN (C0a), minimum load factor A 0.077; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX60",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×72×40 mm envelope and equivalent catalogue ratings; NKX60 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX60-Z",
      "NKX 60 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX60",
    "brand": "SKF",
    "manufacturer_designation": "NKX 60",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 60,
    "D_mm": 72,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 41.8,
    "static_load_kN": 96.5,
    "fatigue_load_limit_kN": 11.8,
    "max_rpm": 5000,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 5000,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 60 mm shaft under radial plus one-direction axial load, NKX 60 from the combined needle roller / thrust ball bearings with caged thrust part provides both in 72×40 mm: needle roller cage below, caged thrust ball set above. The code NKX 60 reads as combined radial/thrust for a 60 mm shaft; the catalogue height 40 mm stacks the radial cage and the thrust set, and the 72 mm OD seats both parts in one bore. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. The minimum load factor A 0.077 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Apply the working axial load after mounting and re-check running torque; a rising torque in the first minutes signals balls climbing the washer lip under reversed thrust.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 60 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 41.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 41.8/96.5 kN ratings and 360 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKX 60 designation read?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 60 mm shaft: 72 mm OD, 40 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      },
      {
        "q": "Can the NKX 60 run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 60 runs directly on the 60 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKX 60 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 60 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 60?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 60 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX60-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×72×40 mm envelope and equivalent catalogue ratings; NKX60-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX60",
      "NKX 60"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX70-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKX 70 Z",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 85,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44.6,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.2,
    "max_rpm": 2700,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 2700,
    "weight_g": 520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKX 70 Z is a combined needle roller / thrust ball bearing with a caged thrust part: radial load on caged needle rollers, axial load on a ball thrust set with stamped cages, per SKF catalogue PUB BU/P1 17000 ch. 7.9. The code NKX 70 Z reads as combined radial/thrust for a 70 mm shaft; the catalogue height 40 mm stacks the radial cage and the thrust set, and the 85 mm OD seats both parts in one bore. Execution notes: the Z suffix adds a shield over the thrust balls, TN a polymer cage; the open execution allows relubrication through the shaft, the Z execution is greased for life. Speed ceilings differ by part: 3,400 r/min thermal reference and 2,700 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: press the unit onto the 70 mm seat against the inner faces, orient the thrust set toward the axial load, and verify the 40 mm overall height against the housing stack after fitting.",
    "applications": [
      "gear pairs generating one-direction axial force",
      "rotary indexing tables under combined load",
      "conveyor screw thrust ends",
      "turntable and swivel mounts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Hardness is load capacity: in families without an inner ring the 70 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 44.6/98 kN ratings are SKF catalogue values for this exact execution (NKX 70 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 43.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKX 70 Z facing the working thrust.",
      "The 44.6/98 kN ratings and 520 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKX 70 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKX 70 Z runs directly on the 70 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKX 70 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 70 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKX 70 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 70 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 7.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKX 70 Z?",
        "a": "A NKX 70 Z measures 70 mm bore/Fw × 85 mm outside diameter × 40 mm width (2.756 × 3.346 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44.6 kN, static C0 98 kN, fatigue limit Pu 12.2 kN, limiting speed 2,700 r/min, reference speed 3,400 r/min, mass about 520 g. Axial ratings of the thrust part: dynamic Ca 43.6 kN (Ca), static C0a 137 kN (C0a), minimum load factor A 0.097; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX70",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 70×85×40 mm envelope and equivalent catalogue ratings; NKX70 is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX70-Z",
      "NKX 70 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKX70",
    "brand": "SKF",
    "manufacturer_designation": "NKX 70",
    "series": "NKX-series",
    "type": "needle",
    "d_mm": 70,
    "D_mm": 85,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 44.6,
    "static_load_kN": 98,
    "fatigue_load_limit_kN": 12.2,
    "max_rpm": 4500,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 4500,
    "weight_g": 500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKX 70 designates a combined bearing with needle roller radial part and caged thrust ball part: 70 mm shaft seat, 85 mm OD, thrust dynamic rating 43.6 kN (Ca). Reading the designation: NKX marks needle roller + caged thrust ball, the number the 70 mm shaft seat; the 85 mm OD and 40 mm overall height come from the series plan. The thrust part takes axial load in one direction only; mount it facing the working load and provide a separate locating bearing for reverse events. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. The caged thrust part survives moderate speed only with the Z shield intact — damaged shields admit grit straight into the ball raceways, and the narrow section leaves no margin.",
    "applications": [
      "turntable and swivel mounts",
      "machine tool feed spindles with one-direction thrust",
      "pump impeller shafts with steady axial pull",
      "gear pairs generating one-direction axial force"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "Above 50 mm bore, thermal growth matters: the 70 mm inner ring or journal grows with temperature faster than the housing, and the small clearance of a needle roller contact leaves little reserve — check running clearance hot, not just at assembly.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKX 70 shares its 70×85×40 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Minimum axial load is a real requirement: below factor A 0.097 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 44.6/98 kN ratings and 500 g mass are SKF catalogue values transcribed from ch. 7.9 of PUB BU/P1 17000 (PDF table page 658); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKX 70?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 70 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKX 70 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKX 70 have?",
        "a": "A NKX 70 measures 70 mm bore/Fw × 85 mm outside diameter × 40 mm width (2.756 × 3.346 × 1.575 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 44.6 kN, static C0 98 kN, fatigue limit Pu 12.2 kN, limiting speed 4,500 r/min, reference speed 3,400 r/min, mass about 500 g. Axial ratings of the thrust part: dynamic Ca 43.6 kN (Ca), static C0a 137 kN (C0a), minimum load factor A 0.097; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKX 70 mean in SKF part numbering?",
        "a": "NKX = needle roller radial part + caged thrust ball part for a 70 mm shaft: 85 mm OD, 40 mm overall height. The caged thrust part trades some axial capacity for higher permissible speed versus NX."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKX70-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 70×85×40 mm envelope and equivalent catalogue ratings; NKX70-Z is the combined needle/thrust ball execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.9 needle roller / thrust ball, caged thrust part",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKX70",
      "NKX 70"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR15",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 15",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 8500,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 8500,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKXR 15 is the heavy-thrust member of the combined needle roller family: 15 mm radial seat, 24 mm OD, and a full complement of thrust needles rated 11.2 kN (Ca) dynamic / 27 kN (C0a) static. The R before the X in NKXR flags the roller (not ball) thrust part; the figure gives the 15 mm seat, and the catalogue completes 24×23 mm. Thrust needle sets tolerate slow speeds and heavy loads: the 8,500 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Selection arithmetic for the combined unit: radial C 11 kN, radial C0 14 kN, axial dynamic 11.2 kN (Ca) and axial static 27 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 15 mm seat.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKXR 15 shares its 15×24×23 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 4,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Do not treat the axial rating 11.2 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 15 facing the working thrust.",
      "The 11/14 kN ratings and 42 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKXR 15 designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 15 mm shaft: 24 mm OD, 23 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Can the NKXR 15 run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 15 runs directly on the 15 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 15 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKXR 15?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 15 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×24×23 mm envelope and equivalent catalogue ratings; NKXR15-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR15",
      "NKXR 15"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR15-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 15 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 11,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 1.66,
    "max_rpm": 8500,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 8500,
    "weight_g": 45,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKXR 15 Z denotes a combined bearing with needle roller radial part and full complement thrust needle part for one-direction axial loads at slow to moderate speed. In SKF nomenclature NKXR is the highest-capacity combined family: 15 mm shaft seat, packed thrust needles above the radial cage, axial rating 11.2 kN (Ca) dynamic. Execution notes: the Z suffix shields the thrust needle set; the full complement part delivers the highest axial rating in the family but needs the minimum axial load (factor A 0.000058) to prevent needle skidding. Axial capability is one-direction: size the arrangement so working thrust pushes the thrust-washer face, and provide a mirrored unit or separate bearing for load reversals. These units run at low speed with high axial load: verify lubricant channeling at the washer faces after the first hour, as the packed thrust set pumps grease axially out of the 23 mm tall envelope.",
    "applications": [
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed",
      "extruder and mixer thrust positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 15 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 24 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 4,300 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 15 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Do not treat the axial rating 11.2 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 15 Z facing the working thrust.",
      "The 11/14 kN ratings and 45 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKXR 15 Z mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 15 mm shaft: 24 mm OD, 23 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 15 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 15 Z runs directly on the 15 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 15 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 15 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKXR 15 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×24×23 mm envelope and equivalent catalogue ratings; NKXR15 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX15-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX15",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (15×24×23 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR15-Z",
      "NKXR 15 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR17",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 17",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 8500,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 8500,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 17 mm shaft under strong one-direction axial load with limited radial space, NKXR 17 from the combined needle roller / full complement needle thrust bearings stacks a caged needle radial part with a full complement thrust needle part: 17×26×25 mm. The code NKXR 17 identifies the construction exactly — needle radial part, needle thrust part — for a 17 mm shaft; the thrust set is one-directional and must face the working axial load. One-direction thrust only — reverse axial loads lift the packed needle set off its raceway; arrange a second unit mirrored or a separate thrust bearing for reversing duty. Selection arithmetic for the combined unit: radial C 12.1 kN, radial C0 16.6 kN, axial dynamic 12.2 kN (Ca) and axial static 31.5 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 17 mm seat.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Minimum axial load is a real requirement: below factor A 0.000079 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 12.1/16.6 kN ratings and 50 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What limits the service life of a NKXR 17?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKXR 17?",
        "a": "A NKXR 17 measures 17 mm bore/Fw × 26 mm outside diameter × 25 mm width (0.669 × 1.024 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 8,500 r/min, reference speed 4,300 r/min, mass about 50 g. Axial ratings of the thrust part: dynamic Ca 12.2 kN (Ca), static C0a 31.5 kN (C0a), minimum load factor A 0.000079; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKXR 17 designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 17 mm shaft: 26 mm OD, 25 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Can the NKXR 17 run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 17 runs directly on the 17 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×26×25 mm envelope and equivalent catalogue ratings; NKXR17-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR17",
      "NKXR 17"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR17-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 17 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 12.1,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.96,
    "max_rpm": 8500,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 8500,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKXR 17 Z denotes a combined bearing with needle roller radial part and full complement thrust needle part for one-direction axial loads at slow to moderate speed. The R before the X in NKXR flags the roller (not ball) thrust part; the figure gives the 17 mm seat, and the catalogue completes 26×25 mm. Thrust needle sets tolerate slow speeds and heavy loads: the 8,500 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. The minimum load factor A 0.000079 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Mounting: the thrust needle complement is held by grease during assembly; fill the washer set, orient toward the axial load, and preload to at least factor A 0.000079 before rotating.",
    "applications": [
      "large valve stems under high axial load",
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 17 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 26 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 17 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.000079 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 12.1/16.6 kN ratings and 53 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKXR 17 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 17 Z runs directly on the 17 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 17 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 17 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKXR 17 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 17 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 4.5 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKXR 17 Z?",
        "a": "A NKXR 17 Z measures 17 mm bore/Fw × 26 mm outside diameter × 25 mm width (0.669 × 1.024 × 0.984 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 12.1 kN, static C0 16.6 kN, fatigue limit Pu 1.96 kN, limiting speed 8,500 r/min, reference speed 4,300 r/min, mass about 53 g. Axial ratings of the thrust part: dynamic Ca 12.2 kN (Ca), static C0a 31.5 kN (C0a), minimum load factor A 0.000079; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×26×25 mm envelope and equivalent catalogue ratings; NKXR17 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX17-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX17",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (17×26×25 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR17-Z",
      "NKXR 17 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR20",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 20",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 30,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 7500,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 7500,
    "weight_g": 80,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / full complement needle thrust bearings execution NKXR 20 measures 20×30×30 mm: radial dynamic 16.5 kN, axial dynamic 18.6 kN (Ca) — the thrust needle complement gives roughly twice the axial rating of a same-size thrust ball part. The R before the X in NKXR flags the roller (not ball) thrust part; the figure gives the 20 mm seat, and the catalogue completes 30×30 mm. One-direction thrust only — reverse axial loads lift the packed needle set off its raceway; arrange a second unit mirrored or a separate thrust bearing for reversing duty. Selection arithmetic for the combined unit: radial C 16.5 kN, radial C0 25.5 kN, axial dynamic 18.6 kN (Ca) and axial static 48 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Mounting: the thrust needle complement is held by grease during assembly; fill the washer set, orient toward the axial load, and preload to at least factor A 0.00018 before rotating.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Do not interchange envelope-identical needle families blindly: NKXR 20 shares its 20×30×30 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Reference and limiting speeds are different limits: the 3,800 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Do not treat the axial rating 18.6 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 20 facing the working thrust.",
      "The 16.5/25.5 kN ratings and 80 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How should the NKXR 20 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKXR 20?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 20 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 5.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKXR 20?",
        "a": "A NKXR 20 measures 20 mm bore/Fw × 30 mm outside diameter × 30 mm width (0.787 × 1.181 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.5 kN, static C0 25.5 kN, fatigue limit Pu 3.05 kN, limiting speed 7,500 r/min, reference speed 3,800 r/min, mass about 80 g. Axial ratings of the thrust part: dynamic Ca 18.6 kN (Ca), static C0a 48 kN (C0a), minimum load factor A 0.00018; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKXR 20 designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 20 mm shaft: 30 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×30×30 mm envelope and equivalent catalogue ratings; NKXR20-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR20",
      "NKXR 20"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR20-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 20 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 20,
    "D_mm": 30,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 16.5,
    "static_load_kN": 25.5,
    "fatigue_load_limit_kN": 3.05,
    "max_rpm": 7500,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 7500,
    "weight_g": 84,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "For a 20 mm shaft under strong one-direction axial load with limited radial space, NKXR 20 Z from the combined needle roller / full complement needle thrust bearings stacks a caged needle radial part with a full complement thrust needle part: 20×30×30 mm. Reading the designation: NKXR marks needle roller + full complement needle thrust, the number the 20 mm shaft seat; 30 mm OD and 30 mm height follow the series plan. Execution notes: the Z suffix shields the thrust needle set; the full complement part delivers the highest axial rating in the family but needs the minimum axial load (factor A 0.00018) to prevent needle skidding. Speed ceilings differ by part: 3,800 r/min thermal reference and 7,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. These units run at low speed with high axial load: verify lubricant channeling at the washer faces after the first hour, as the packed thrust set pumps grease axially out of the 30 mm tall envelope.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "hard-particle indentation in unfiltered lubricant",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "On a 20 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 30 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "The quoted 16.5/25.5 kN ratings are SKF catalogue values for this exact execution (NKXR 20 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 20 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.00018 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 16.5/25.5 kN ratings and 84 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKXR 20 Z have?",
        "a": "A NKXR 20 Z measures 20 mm bore/Fw × 30 mm outside diameter × 30 mm width (0.787 × 1.181 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 16.5 kN, static C0 25.5 kN, fatigue limit Pu 3.05 kN, limiting speed 7,500 r/min, reference speed 3,800 r/min, mass about 84 g. Axial ratings of the thrust part: dynamic Ca 18.6 kN (Ca), static C0a 48 kN (C0a), minimum load factor A 0.00018; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKXR 20 Z mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 20 mm shaft: 30 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 20 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 20 Z runs directly on the 20 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 20 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 20 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×30×30 mm envelope and equivalent catalogue ratings; NKXR20 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX20-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX20",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (20×30×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR20-Z",
      "NKXR 20 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR25",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 25",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 6300,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 6300,
    "weight_g": 120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKXR 25 is a combined needle roller / full complement needle thrust bearing: caged needle rollers for radial duty plus a packed needle thrust set for the highest axial capacity of any 25 mm combined bearing, per SKF catalogue PUB BU/P1 17000 ch. 7.10. In SKF nomenclature NKXR is the highest-capacity combined family: 25 mm shaft seat, packed thrust needles above the radial cage, axial rating 25 kN (Ca) dynamic. Execution notes: the Z suffix shields the thrust needle set; the full complement part delivers the highest axial rating in the family but needs the minimum axial load (factor A 0.00039) to prevent needle skidding. Speed ceilings differ by part: 3,200 r/min thermal reference and 6,300 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: the thrust needle complement is held by grease during assembly; fill the washer set, orient toward the axial load, and preload to at least factor A 0.00039 before rotating.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Reference and limiting speeds are different limits: the 3,200 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 25 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 19/32.5 kN ratings and 120 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What mounting mistakes ruin a NKXR 25?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKXR 25 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKXR 25 have?",
        "a": "A NKXR 25 measures 25 mm bore/Fw × 37 mm outside diameter × 30 mm width (0.984 × 1.457 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 19 kN, static C0 32.5 kN, fatigue limit Pu 4 kN, limiting speed 6,300 r/min, reference speed 3,200 r/min, mass about 120 g. Axial ratings of the thrust part: dynamic Ca 25 kN (Ca), static C0a 69.5 kN (C0a), minimum load factor A 0.00039; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKXR 25 mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 25 mm shaft: 37 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×37×30 mm envelope and equivalent catalogue ratings; NKXR25-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 35.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR25",
      "NKXR 25"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR25-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 25 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 19,
    "static_load_kN": 32.5,
    "fatigue_load_limit_kN": 4,
    "max_rpm": 6300,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 6300,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, NKXR 25 Z denotes a combined bearing with needle roller radial part and full complement thrust needle part for one-direction axial loads at slow to moderate speed. The code NKXR 25 Z identifies the construction exactly — needle radial part, needle thrust part — for a 25 mm shaft; the thrust set is one-directional and must face the working axial load. Thrust needle sets tolerate slow speeds and heavy loads: the 6,300 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Speed ceilings differ by part: 3,200 r/min thermal reference and 6,300 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: the thrust needle complement is held by grease during assembly; fill the washer set, orient toward the axial load, and preload to at least factor A 0.00039 before rotating.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "rolling-contact fatigue spalling after the rated L10 life",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "On a 25 mm seat the housing bore quality dominates life: a bore 0.02 mm out of round pinches the 37 mm ring or cup into a lobed shape, and the rollers then trace the housing's geometry error, not the design load.",
      "Hardness is load capacity: in families without an inner ring the 25 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 19/32.5 kN ratings are SKF catalogue values for this exact execution (NKXR 25 Z); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Do not treat the axial rating 25 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 25 Z facing the working thrust.",
      "The 19/32.5 kN ratings and 130 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKXR 25 Z designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 25 mm shaft: 37 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Can the NKXR 25 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 25 Z runs directly on the 25 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 25 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 25 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKXR 25 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 25 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×37×30 mm envelope and equivalent catalogue ratings; NKXR25 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 35.2/53 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25-Z",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX25",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×30 mm envelope, but catalogue C/C0 differ between the executions (19/32.5 vs 15.1/24.5 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX25-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX25",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (25×37×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR25-Z",
      "NKXR 25 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR30",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 30",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 6000,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 6000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKXR 30 where axial capacity dominates: the packed thrust needle set carries 27 kN (Ca) dynamically at the cost of speed, while the caged radial rollers contribute 22.9 kN. In SKF nomenclature NKXR is the highest-capacity combined family: 30 mm shaft seat, packed thrust needles above the radial cage, axial rating 27 kN (Ca) dynamic. Thrust needle sets tolerate slow speeds and heavy loads: the 6,000 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Speed ceilings differ by part: 3,000 r/min thermal reference and 6,000 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. These units run at low speed with high axial load: verify lubricant channeling at the washer faces after the first hour, as the packed thrust set pumps grease axially out of the 30 mm tall envelope.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 3,000 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 30 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "Do not treat the axial rating 27 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The 22.9/38 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKXR 30 have?",
        "a": "A NKXR 30 measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 6,000 r/min, reference speed 3,000 r/min, mass about 140 g. Axial ratings of the thrust part: dynamic Ca 27 kN (Ca), static C0a 78 kN (C0a), minimum load factor A 0.00049; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKXR 30 mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 30 mm shaft: 42 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 30 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 30 runs directly on the 30 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 30?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×42×30 mm envelope and equivalent catalogue ratings; NKXR30-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (22.9/38 vs 38/62 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR30",
      "NKXR 30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR30-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 30 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 22.9,
    "static_load_kN": 38,
    "fatigue_load_limit_kN": 4.8,
    "max_rpm": 6000,
    "reference_speed_rpm": 3000,
    "limiting_speed_rpm": 6000,
    "weight_g": 140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKXR 30 Z where axial capacity dominates: the packed thrust needle set carries 27 kN (Ca) dynamically at the cost of speed, while the caged radial rollers contribute 22.9 kN. The R before the X in NKXR flags the roller (not ball) thrust part; the figure gives the 30 mm seat, and the catalogue completes 42×30 mm. Execution notes: the Z suffix shields the thrust needle set; the full complement part delivers the highest axial rating in the family but needs the minimum axial load (factor A 0.00049) to prevent needle skidding. The minimum load factor A 0.00049 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 30 mm seat.",
    "applications": [
      "large valve stems under high axial load",
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 30 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 30 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 30 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.00049 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 22.9/38 kN ratings and 140 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKXR 30 Z?",
        "a": "A NKXR 30 Z measures 30 mm bore/Fw × 42 mm outside diameter × 30 mm width (1.181 × 1.654 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 22.9 kN, static C0 38 kN, fatigue limit Pu 4.8 kN, limiting speed 6,000 r/min, reference speed 3,000 r/min, mass about 140 g. Axial ratings of the thrust part: dynamic Ca 27 kN (Ca), static C0a 78 kN (C0a), minimum load factor A 0.00049; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKXR 30 Z designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 30 mm shaft: 42 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Can the NKXR 30 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 30 Z runs directly on the 30 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 30 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 30 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×42×30 mm envelope and equivalent catalogue ratings; NKXR30 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×30 mm envelope, but catalogue C/C0 differ between the executions (22.9/38 vs 38/62 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX30-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×42×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR30-Z",
      "NKXR 30 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR35",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 35",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 5600,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 5600,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKXR 35 is the heavy-thrust member of the combined needle roller family: 35 mm radial seat, 47 mm OD, and a full complement of thrust needles rated 29 kN (Ca) dynamic / 93 kN (C0a) static. The code NKXR 35 identifies the construction exactly — needle radial part, needle thrust part — for a 35 mm shaft; the thrust set is one-directional and must face the working axial load. One-direction thrust only — reverse axial loads lift the packed needle set off its raceway; arrange a second unit mirrored or a separate thrust bearing for reversing duty. Selection arithmetic for the combined unit: radial C 24.6 kN, radial C0 45 kN, axial dynamic 29 kN (Ca) and axial static 93 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. These units run at low speed with high axial load: verify lubricant channeling at the washer faces after the first hour, as the packed thrust set pumps grease axially out of the 30 mm tall envelope.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 35 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 24.6/45 kN ratings are SKF catalogue values for this exact execution (NKXR 35); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Minimum axial load is a real requirement: below factor A 0.00069 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 24.6/45 kN ratings and 160 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the NKXR 35?",
        "a": "A NKXR 35 measures 35 mm bore/Fw × 47 mm outside diameter × 30 mm width (1.378 × 1.85 × 1.181 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 24.6 kN, static C0 45 kN, fatigue limit Pu 5.6 kN, limiting speed 5,600 r/min, reference speed 2,800 r/min, mass about 160 g. Axial ratings of the thrust part: dynamic Ca 29 kN (Ca), static C0a 93 kN (C0a), minimum load factor A 0.00069; the thrust set carries load in one direction only."
      },
      {
        "q": "How is the NKXR 35 designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 35 mm shaft: 47 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Can the NKXR 35 run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 35 runs directly on the 35 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 35 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×47×30 mm envelope and equivalent catalogue ratings; NKXR35-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (24.6/45 vs 42.9/75 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR35",
      "NKXR 35"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR35-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 35 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 5.6,
    "max_rpm": 5600,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 5600,
    "weight_g": 170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / full complement needle thrust bearings execution NKXR 35 Z measures 35×47×30 mm: radial dynamic 24.6 kN, axial dynamic 29 kN (Ca) — the thrust needle complement gives roughly twice the axial rating of a same-size thrust ball part. The code NKXR 35 Z identifies the construction exactly — needle radial part, needle thrust part — for a 35 mm shaft; the thrust set is one-directional and must face the working axial load. Thrust needle sets tolerate slow speeds and heavy loads: the 5,600 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Speed ceilings differ by part: 2,800 r/min thermal reference and 5,600 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. These units run at low speed with high axial load: verify lubricant channeling at the washer faces after the first hour, as the packed thrust set pumps grease axially out of the 30 mm tall envelope.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "electrical erosion on VFD-driven shafts without brush or insulated mounting",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 35 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 35 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not treat the axial rating 29 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 35 Z facing the working thrust.",
      "The 24.6/45 kN ratings and 170 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "How is the NKXR 35 Z designation read?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 35 mm shaft: 47 mm OD, 30 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Can the NKXR 35 Z run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 35 Z runs directly on the 35 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 35 Z be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 35 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKXR 35 Z?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 35 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×47×30 mm envelope and equivalent catalogue ratings; NKXR35 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "RNA6906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×30 mm envelope, but catalogue C/C0 differ between the executions (24.6/45 vs 42.9/75 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX35-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX35",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×47×30 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR35-Z",
      "NKXR 35 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR40",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 40",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 5000,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 5000,
    "weight_g": 200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "The combined needle roller / full complement needle thrust bearings execution NKXR 40 measures 40×52×32 mm: radial dynamic 26.4 kN, axial dynamic 43 kN (Ca) — the thrust needle complement gives roughly twice the axial rating of a same-size thrust ball part. The code NKXR 40 identifies the construction exactly — needle radial part, needle thrust part — for a 40 mm shaft; the thrust set is one-directional and must face the working axial load. Execution notes: the Z suffix shields the thrust needle set; the full complement part delivers the highest axial rating in the family but needs the minimum axial load (factor A 0.0015) to prevent needle skidding. Selection arithmetic for the combined unit: radial C 26.4 kN, radial C0 51 kN, axial dynamic 43 kN (Ca) and axial static 137 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 40 mm seat.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after overload events",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "false brinelling of standby equipment under external vibration",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Hardness is load capacity: in families without an inner ring the 40 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The quoted 26.4/51 kN ratings are SKF catalogue values for this exact execution (NKXR 40); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Minimum axial load is a real requirement: below factor A 0.0015 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "Height stack-up is easy to mis-check: the thrust-washer part adds height beyond a plain needle bearing, and clamping the stack solid over it preloads the thrust set beyond its rating.",
      "The 26.4/51 kN ratings and 200 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Can the NKXR 40 run on an unhardened shaft?",
        "a": "The radial needle part of the NKXR 40 runs directly on the 40 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "How should the NKXR 40 be mounted?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "What limits the service life of a NKXR 40?",
        "a": "Beyond the L10 rating, the practical limits are journal/raceway hardness for the 40 mm seat, lubricant condition at the roller ends, and contamination through open ends — the 6.0 mm radial section leaves no reserve once a raceway is dented or ribboned."
      },
      {
        "q": "What are the dimensions and ratings of the NKXR 40?",
        "a": "A NKXR 40 measures 40 mm bore/Fw × 52 mm outside diameter × 32 mm width (1.575 × 2.047 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 5,000 r/min, reference speed 2,400 r/min, mass about 200 g. Axial ratings of the thrust part: dynamic Ca 43 kN (Ca), static C0a 137 kN (C0a), minimum load factor A 0.0015; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR40-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×52×32 mm envelope and equivalent catalogue ratings; NKXR40-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX40-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX40",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR40",
      "NKXR 40"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR40-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 40 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 26.4,
    "static_load_kN": 51,
    "fatigue_load_limit_kN": 6.3,
    "max_rpm": 5000,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 5000,
    "weight_g": 210,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKXR 40 Z where axial capacity dominates: the packed thrust needle set carries 43 kN (Ca) dynamically at the cost of speed, while the caged radial rollers contribute 26.4 kN. In SKF nomenclature NKXR is the highest-capacity combined family: 40 mm shaft seat, packed thrust needles above the radial cage, axial rating 43 kN (Ca) dynamic. Thrust needle sets tolerate slow speeds and heavy loads: the 5,000 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Selection arithmetic for the combined unit: radial C 26.4 kN, radial C0 51 kN, axial dynamic 43 kN (Ca) and axial static 137 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. These units run at low speed with high axial load: verify lubricant channeling at the washer faces after the first hour, as the packed thrust set pumps grease axially out of the 32 mm tall envelope.",
    "applications": [
      "extruder and mixer thrust positions",
      "large valve stems under high axial load",
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "hard-particle indentation in unfiltered lubricant",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 40 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 40 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKXR 40 Z shares its 40×52×32 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 40 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.0015 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 26.4/51 kN ratings and 210 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKXR 40 Z have?",
        "a": "A NKXR 40 Z measures 40 mm bore/Fw × 52 mm outside diameter × 32 mm width (1.575 × 2.047 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 26.4 kN, static C0 51 kN, fatigue limit Pu 6.3 kN, limiting speed 5,000 r/min, reference speed 2,400 r/min, mass about 210 g. Axial ratings of the thrust part: dynamic Ca 43 kN (Ca), static C0a 137 kN (C0a), minimum load factor A 0.0015; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKXR 40 Z mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 40 mm shaft: 52 mm OD, 32 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 40 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 40 Z runs directly on the 40 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 40 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 40 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR40",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×52×32 mm envelope and equivalent catalogue ratings; NKXR40 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX40-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX40",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×52×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR40-Z",
      "NKXR 40 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR45",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 45",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 4500,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 4500,
    "weight_g": 240,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKXR 45 is a combined needle roller / full complement needle thrust bearing: caged needle rollers for radial duty plus a packed needle thrust set for the highest axial capacity of any 45 mm combined bearing, per SKF catalogue PUB BU/P1 17000 ch. 7.10. Reading the designation: NKXR marks needle roller + full complement needle thrust, the number the 45 mm shaft seat; 58 mm OD and 32 mm height follow the series plan. Thrust needle sets tolerate slow speeds and heavy loads: the 4,500 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Speed ceilings differ by part: 2,200 r/min thermal reference and 4,500 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 45 mm seat.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 27.5/57 kN ratings are SKF catalogue values for this exact execution (NKXR 45); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 45 facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.0019 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 27.5/57 kN ratings and 240 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Does the NKXR 45 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 45 runs directly on the 45 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 45?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKXR 45 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKXR 45 have?",
        "a": "A NKXR 45 measures 45 mm bore/Fw × 58 mm outside diameter × 32 mm width (1.772 × 2.283 × 1.26 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 27.5 kN, static C0 57 kN, fatigue limit Pu 7.1 kN, limiting speed 4,500 r/min, reference speed 2,200 r/min, mass about 240 g. Axial ratings of the thrust part: dynamic Ca 45 kN (Ca), static C0a 153 kN (C0a), minimum load factor A 0.0019; the thrust set carries load in one direction only."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR45-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×58×32 mm envelope and equivalent catalogue ratings; NKXR45-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX45-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX45",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR45",
      "NKXR 45"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR45-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 45 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 27.5,
    "static_load_kN": 57,
    "fatigue_load_limit_kN": 7.1,
    "max_rpm": 4500,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 4500,
    "weight_g": 260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKXR 45 Z is a combined needle roller / full complement needle thrust bearing: caged needle rollers for radial duty plus a packed needle thrust set for the highest axial capacity of any 45 mm combined bearing, per SKF catalogue PUB BU/P1 17000 ch. 7.10. Reading the designation: NKXR marks needle roller + full complement needle thrust, the number the 45 mm shaft seat; 58 mm OD and 32 mm height follow the series plan. Thrust needle sets tolerate slow speeds and heavy loads: the 4,500 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. The minimum load factor A 0.0019 applies to the thrust part: below that axial load the rolling elements of the thrust set skid, so springs or preload washers are part of the arrangement, not an afterthought. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 45 mm seat.",
    "applications": [
      "large valve stems under high axial load",
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "cage pocket wear and roller skew after sustained operation with too little radial preload",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "false brinelling of standby equipment under external vibration",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 45 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 45 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Contamination, not fatigue, kills most small needle bearings: with raceways this narrow, one hard particle dents a full-width line — seal the housing even when the bearing execution itself is open.",
      "Do not interchange envelope-identical needle families blindly: NKXR 45 Z shares its 45×58×32 mm outline with inner-ring and sealed siblings whose ratings differ — the family letters are part of the specification, not decoration.",
      "Do not treat the axial rating 45 kN (Ca) as independent of radial load: the combined equivalent load formulas couple them, and a unit sized on radial life alone will spall the ball raceway first under real thrust.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 45 Z facing the working thrust.",
      "The 27.5/57 kN ratings and 260 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "What does NKXR 45 Z mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 45 mm shaft: 58 mm OD, 32 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 45 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 45 Z runs directly on the 45 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 45 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 45 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      },
      {
        "q": "Is the NKXR 45 Z sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR45",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×58×32 mm envelope and equivalent catalogue ratings; NKXR45 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NKX45-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX45",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (45×58×32 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR45-Z",
      "NKXR 45 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR50",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 50",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 62,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 4300,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 4300,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "SKF lists NKXR 50 where axial capacity dominates: the packed thrust needle set carries 47.5 kN (Ca) dynamically at the cost of speed, while the caged radial rollers contribute 38 kN. Reading the designation: NKXR marks needle roller + full complement needle thrust, the number the 50 mm shaft seat; 62 mm OD and 35 mm height follow the series plan. One-direction thrust only — reverse axial loads lift the packed needle set off its raceway; arrange a second unit mirrored or a separate thrust bearing for reversing duty. Speed ceilings differ by part: 2,200 r/min thermal reference and 4,300 r/min limiting — the thrust element governs, since its washer faces see sliding components of contact. Mounting: the thrust needle complement is held by grease during assembly; fill the washer set, orient toward the axial load, and preload to at least factor A 0.0022 before rotating.",
    "applications": [
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions",
      "heavy screw presses and clamping spindles",
      "crane slew rings and kingposts at low speed"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "abrasive paste formation from dust ingressing past open ends without effective housing seals",
      "corrosion pitting from condensation in intermittently operated machinery",
      "thrust-part ball or roller skidding and smearing when the axial load falls below the minimum factor"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "The quoted 38/78 kN ratings are SKF catalogue values for this exact execution (NKXR 50); ratings can be revised without the order number changing, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the drawing.",
      "Oscillating pivots fail differently: rocking through a small angle concentrates wear in the same roller positions — inspect those zones, and consider rotating the assembly's clock position at service intervals.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 50 facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.0022 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 38/78 kN ratings and 270 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Is the NKXR 50 sealed?",
        "a": "No — this execution is open and depends on the housing sealing arrangement; grease it at assembly and keep the relubrication interval short in dirty duty."
      },
      {
        "q": "Which dimensions does the NKXR 50 have?",
        "a": "A NKXR 50 measures 50 mm bore/Fw × 62 mm outside diameter × 35 mm width (1.969 × 2.441 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 4,300 r/min, reference speed 2,200 r/min, mass about 270 g. Axial ratings of the thrust part: dynamic Ca 47.5 kN (Ca), static C0a 166 kN (C0a), minimum load factor A 0.0022; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKXR 50 mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 50 mm shaft: 62 mm OD, 35 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 50 need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 50 runs directly on the 50 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR50-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×62×35 mm envelope and equivalent catalogue ratings; NKXR50-Z is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NK50-35-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (38/78 vs 58.3/137 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX50-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX50",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR50",
      "NKXR 50"
    ],
    "locale_variants": {}
  },
  {
    "sku": "NKXR50-Z",
    "brand": "SKF",
    "manufacturer_designation": "NKXR 50 Z",
    "series": "NKXR-series",
    "type": "needle",
    "d_mm": 50,
    "D_mm": 62,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 38,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 9.65,
    "max_rpm": 4300,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 4300,
    "weight_g": 290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "DIN 616",
    "naming_rule_text": "NKXR 50 Z is the heavy-thrust member of the combined needle roller family: 50 mm radial seat, 62 mm OD, and a full complement of thrust needles rated 47.5 kN (Ca) dynamic / 166 kN (C0a) static. In SKF nomenclature NKXR is the highest-capacity combined family: 50 mm shaft seat, packed thrust needles above the radial cage, axial rating 47.5 kN (Ca) dynamic. Thrust needle sets tolerate slow speeds and heavy loads: the 4,300 r/min limiting speed is far below ball-thrust equivalents, and lubricant film at the washer faces governs life. Selection arithmetic for the combined unit: radial C 38 kN, radial C0 78 kN, axial dynamic 47.5 kN (Ca) and axial static 166 kN (C0a); combine them with the equivalent-load factors from the catalogue before checking L10. Fit with a press against the washer faces only — needles packed without a cage will skew if the assembly is dropped or driven sideways onto the 50 mm seat.",
    "applications": [
      "extruder and mixer thrust positions",
      "large valve stems under high axial load",
      "turntables and slewing pivots with shock loads",
      "press-fit die set guide positions"
    ],
    "failure_modes": [
      "needle edge loading and raceway denting when the shaft deflects beyond the compensation range",
      "polymer cage deformation when the local temperature exceeds the 120 °C sustained limit",
      "grease starvation at the roller ends when relubrication intervals are stretched in dirty duty",
      "brinelling of raceways from impact or pressing force transmitted through the rolling elements",
      "thrust washer raceway wear from reverse axial shocks the one-direction thrust part cannot carry"
    ],
    "pitfalls": [
      "At 50 mm bore, verify shaft deflection against the needle length: these rollers tolerate little edge loading, and a simply supported span between 50 mm seats can bend past the compensation range long before the load rating is exhausted.",
      "Reference and limiting speeds are different limits: the 2,200 r/min reference is the thermal criterion under load, The limiting value is mechanical; the reference value is thermal under load, and grease choice moves it substantially.",
      "Hardness is load capacity: in families without an inner ring the 50 mm journal must hold 58–64 HRC with a ground finish; a surface that looks fine but sits at 45 HRC will rib the raceway within weeks.",
      "The thrust part is one-direction: reverse axial events — however brief — lift the rolling elements off the raceway, and the subsequent re-entry impact dents the washer face; mount the NKXR 50 Z facing the working thrust.",
      "Minimum axial load is a real requirement: below factor A 0.0022 the thrust elements skid, polish their raceways and lose them — springs or preload washers belong in the arrangement drawing, not the troubleshooting notes.",
      "The 38/78 kN ratings and 290 g mass are SKF catalogue values transcribed from ch. 7.10 of PUB BU/P1 17000 (PDF table page 660); combined-type axial ratings appear in the text above because the structured record carries radial values only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the NKXR 50 Z have?",
        "a": "A NKXR 50 Z measures 50 mm bore/Fw × 62 mm outside diameter × 35 mm width (1.969 × 2.441 × 1.378 in). From SKF catalogue PUB BU/P1 17000: radial dynamic rating C 38 kN, static C0 78 kN, fatigue limit Pu 9.65 kN, limiting speed 4,300 r/min, reference speed 2,200 r/min, mass about 290 g. Axial ratings of the thrust part: dynamic Ca 47.5 kN (Ca), static C0a 166 kN (C0a), minimum load factor A 0.0022; the thrust set carries load in one direction only."
      },
      {
        "q": "What does NKXR 50 Z mean in SKF part numbering?",
        "a": "NKXR = needle roller radial part + full complement needle thrust part for a 50 mm shaft: 62 mm OD, 35 mm overall height, the highest axial rating of the combined needle families."
      },
      {
        "q": "Does the NKXR 50 Z need a hardened and ground shaft?",
        "a": "The radial needle part of the NKXR 50 Z runs directly on the 50 mm journal — harden to 58–64 HRC and grind it. The thrust washers are integral, so no separate inner ring exists; size the shaft for the raceway tolerances in the catalogue table."
      },
      {
        "q": "What mounting mistakes ruin a NKXR 50 Z?",
        "a": "Press on the ring faces only with a fitting sleeve, keep everything square to the 50 mm seat, and never transmit force through the rolling elements. Follow the catalogue's seat tolerances — the narrow needle contact forgives neither tilt nor burrs."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "NKXR50",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×62×35 mm envelope and equivalent catalogue ratings; NKXR50 is the combined needle/thrust needle execution — boundary-dimension interchangeable, execution differences (seals, shields, cage) apply."
      },
      {
        "equiv_sku": "NK50-35-TN",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×62×35 mm envelope, but catalogue C/C0 differ between the executions (38/78 vs 58.3/137 kN) — boundary dimensions match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "NKX50-Z",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      },
      {
        "equiv_sku": "NKX50",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×62×35 mm) combined needle/thrust ball execution with ratings within 10 % — substitution possible after checking ring/flange construction."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings/needle-roller-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 7.10 needle roller / cylindrical-needle thrust",
    "extracted_at": "2026-09-26",
    "last_verified": "2026-09-26",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "NKXR50-Z",
      "NKXR 50 Z"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6006-V",
    "brand": "SKF",
    "manufacturer_designation": "C 6006 V",
    "series": "C6000-series",
    "type": "carb_toroidal",
    "d_mm": 30,
    "D_mm": 55,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 134,
    "static_load_kN": 180,
    "fatigue_load_limit_kN": 21.2,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 490,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 6006 V: the toroidal rollers allow the 30 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (60) identify the ISO dimension series and the last two (06) encode the 30 mm bore; suffixes describe bore and execution. The cylindrical 30 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 30×55×45 mm are identical — only the mounting method changes. The 490 g mass over the 30×55×45 mm envelope yields about 4.47 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 45 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 30 mm bore the small CARB executions are unusually wide (45 mm) for their 55 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 30 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 6006 V must float; the two are designed to be used as a pair.",
      "The 134/180 kN ratings and 490 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 6006 V have?",
        "a": "A C 6006 V measures 30 mm bore × 55 mm outside diameter × 45 mm width (1.181 × 2.165 × 1.772 in). From SKF catalogue PUB BU/P1 17000: dynamic C 134 kN, static C0 180 kN, fatigue limit Pu 21.2 kN, limiting speed 3,200 r/min, no reference speed listed, mass about 490 g."
      },
      {
        "q": "What does C 6006 V mean in SKF part numbering?",
        "a": "C marks CARB; 60 the dimension series; the size code gives 30 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 6006 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 6006 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6006",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6006-V",
      "C 6006 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2206-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2206 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 69.5,
    "static_load_kN": 62,
    "fatigue_load_limit_kN": 7.2,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 280,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2206 TN9 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 30 mm bore, 62 mm outside diameter, 20 mm wide unit rated 69.5 kN dynamic. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (06) encode the 30 mm bore; suffixes describe bore and execution. The TN9 suffix marks a glass fibre reinforced PA66 cage: lower friction and quieter than the full-complement V execution, with a 11,000 r/min reference speed, the usual choice for continuous-duty fans and paper rolls. The 280 g mass over the 30×62×20 mm envelope yields about 2.32 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: slide the bearing onto the 30 mm seat or heat it (max 120 °C) and seat it square; never press through the 20 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 30 mm bore the small CARB executions are unusually wide (20 mm) for their 62 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2206 TN9 must float; the two are designed to be used as a pair.",
      "Never use C 2206 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 30 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 69.5/62 kN ratings and 280 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 2206 TN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 30 mm bore; TN9 is the execution (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2206 TN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2206 TN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2206-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×62×20 mm ISO 15 envelope and equivalent catalogue C/C0; C 2206 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2206-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×20 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (69.5/62 kN vs 76.5/71 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22206",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×62×20 mm) SKF spherical roller bearing SKF 22206 E with ratings within 10 % — not a drop-in substitute: SKF 22206 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22206-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×62×20 mm) SKF spherical roller bearing SKF 22206 EK with ratings within 10 % — not a drop-in substitute: SKF 22206 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2206-TN9",
      "C 2206 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2206-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2206 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 69.5,
    "static_load_kN": 62,
    "fatigue_load_limit_kN": 7.2,
    "reference_speed_rpm": 11000,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 280,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2206 KTN9 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 30 mm bore, 62 mm outside diameter, 20 mm wide unit rated 69.5 kN dynamic. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (06) encode the 30 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 30 mm shaft deflects; the 11,000 r/min reference and 15,000 r/min limiting speed are both catalogue values. Speed planning separates the 11,000 r/min thermal reference from the 15,000 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the TN9-caged executions run faster and cooler at light load. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 62 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 30 mm bore the small CARB executions are unusually wide (20 mm) for their 62 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 69.5/62 kN ratings belong to this exact execution (C 2206 KTN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 30 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 11,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 69.5/62 kN ratings and 280 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2206 KTN9 have?",
        "a": "A C 2206 KTN9 measures 30 mm bore × 62 mm outside diameter × 20 mm width (1.181 × 2.441 × 0.787 in). From SKF catalogue PUB BU/P1 17000: dynamic C 69.5 kN, static C0 62 kN, fatigue limit Pu 7.2 kN, reference speed 11,000 r/min, limiting speed 15,000 r/min, mass about 280 g."
      },
      {
        "q": "What does C 2206 KTN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 30 mm bore; KTN9 is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2206 KTN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2206-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×62×20 mm ISO 15 envelope and equivalent catalogue C/C0; C 2206 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2206-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×20 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (69.5/62 kN vs 76.5/71 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22206",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×62×20 mm) SKF spherical roller bearing SKF 22206 E with ratings within 10 % — not a drop-in substitute: SKF 22206 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22206-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (30×62×20 mm) SKF spherical roller bearing SKF 22206 EK with ratings within 10 % — not a drop-in substitute: SKF 22206 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2206-KTN9",
      "C 2206 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2206-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2206 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 71,
    "fatigue_load_limit_kN": 8.3,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2206 V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 30×62×20 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. In C 2206 V the 22 dimension series fixes the 62 mm OD and 20 mm width around the 30 mm bore (code 06 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 30 mm seat. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 6,000 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: slide the bearing onto the 30 mm seat or heat it (max 120 °C) and seat it square; never press through the 20 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 30 mm bore the small CARB executions are unusually wide (20 mm) for their 62 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Never use C 2206 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 30 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The quoted 76.5/71 kN ratings belong to this exact execution (C 2206 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 76.5/71 kN ratings and 290 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (76.5 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2206 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 2206 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 30 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 20 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2206 V?",
        "a": "A C 2206 V measures 30 mm bore × 62 mm outside diameter × 20 mm width (1.181 × 2.441 × 0.787 in). From SKF catalogue PUB BU/P1 17000: dynamic C 76.5 kN, static C0 71 kN, fatigue limit Pu 8.3 kN, limiting speed 6,000 r/min, no reference speed listed, mass about 290 g."
      },
      {
        "q": "Can a CARB bearing like C 2206 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 2206 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2206-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×20 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (76.5/71 kN vs 69.5/62 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2206-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×20 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (76.5/71 kN vs 69.5/62 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×20 mm envelope as the SKF spherical roller bearing SKF 22206 E, but catalogue C/C0 differ (76.5/71 kN vs 66.1/60 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22206-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×20 mm envelope as the SKF spherical roller bearing SKF 22206 EK, but catalogue C/C0 differ (76.5/71 kN vs 66.1/60 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2206-V",
      "C 2206 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2207-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2207 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 83,
    "static_load_kN": 80,
    "fatigue_load_limit_kN": 9.3,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 440,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2207 TN9 belongs to the CARB family — compact aligning roller bearings: envelope 35×72×23 mm, radial rating 83/80 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (07) encode the 35 mm bore; suffixes describe bore and execution. The cylindrical 35 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 35×72×23 mm are identical — only the mounting method changes. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2207 TN9 deliberately carries none. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 23 mm wide cavity does not fill itself.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 35 mm bore the small CARB executions are unusually wide (23 mm) for their 72 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 83/80 kN ratings belong to this exact execution (C 2207 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2207 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 35 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 83/80 kN ratings and 440 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 2207 TN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2207 TN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2207 TN9 have?",
        "a": "A C 2207 TN9 measures 35 mm bore × 72 mm outside diameter × 23 mm width (1.378 × 2.835 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 83 kN, static C0 80 kN, fatigue limit Pu 9.3 kN, reference speed 9,500 r/min, limiting speed 13,000 r/min, mass about 440 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2207-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×72×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2207 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2207-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (83/80 kN vs 95/96 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22207",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×72×23 mm) SKF spherical roller bearing SKF 22207 E with ratings within 10 % — not a drop-in substitute: SKF 22207 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22207-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×72×23 mm) SKF spherical roller bearing SKF 22207 EK with ratings within 10 % — not a drop-in substitute: SKF 22207 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2207-TN9",
      "C 2207 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2207-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2207 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 83,
    "static_load_kN": 80,
    "fatigue_load_limit_kN": 9.3,
    "reference_speed_rpm": 9500,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 440,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2207 KTN9 is the dimension series 22 CARB toroidal roller bearings member of the CARB range: 35 mm bore, 72 mm OD, 23 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 2207 KTN9 separates into C (CARB), 22 (dimension series), 07 (35 mm bore) and KTN9 (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage); envelope 35×72×23 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 35 mm seat. Selection arithmetic: C 83 kN against C0 80 kN gives a C0/C ratio of 0.96, and the 9.3 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 72 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 35 mm bore the small CARB executions are unusually wide (23 mm) for their 72 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Never use C 2207 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 35 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The quoted 83/80 kN ratings belong to this exact execution (C 2207 KTN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 83/80 kN ratings and 440 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 2207 KTN9 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 07 = 35 mm bore (code 07 × 5); suffix KTN9 selects tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (83 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2207 KTN9 is the tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage."
      },
      {
        "q": "How is C 2207 KTN9 mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2207 KTN9?",
        "a": "A C 2207 KTN9 measures 35 mm bore × 72 mm outside diameter × 23 mm width (1.378 × 2.835 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 83 kN, static C0 80 kN, fatigue limit Pu 9.3 kN, reference speed 9,500 r/min, limiting speed 13,000 r/min, mass about 440 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2207-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×72×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2207 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2207-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×23 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (83/80 kN vs 95/96 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22207",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×72×23 mm) SKF spherical roller bearing SKF 22207 E with ratings within 10 % — not a drop-in substitute: SKF 22207 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22207-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (35×72×23 mm) SKF spherical roller bearing SKF 22207 EK with ratings within 10 % — not a drop-in substitute: SKF 22207 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2207-KTN9",
      "C 2207 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2207-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2207 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 95,
    "static_load_kN": 96,
    "fatigue_load_limit_kN": 11.2,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2207 V belongs to the CARB family — compact aligning roller bearings: envelope 35×72×23 mm, radial rating 95/96 kN C/C0, and no axial-locating function by design. SKF builds the CARB order number from size plus execution: the bare number C 2207 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The cylindrical 35 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 35×72×23 mm are identical — only the mounting method changes. The 460 g mass over the 35×72×23 mm envelope yields about 2.71 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: slide the bearing onto the 35 mm seat or heat it (max 120 °C) and seat it square; never press through the 23 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 35 mm bore the small CARB executions are unusually wide (23 mm) for their 72 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2207 V must float; the two are designed to be used as a pair.",
      "Never use C 2207 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 95/96 kN ratings belong to this exact execution (C 2207 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 95/96 kN ratings and 460 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2207 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2207 V have?",
        "a": "A C 2207 V measures 35 mm bore × 72 mm outside diameter × 23 mm width (1.378 × 2.835 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 95 kN, static C0 96 kN, fatigue limit Pu 11.2 kN, limiting speed 5,300 r/min, no reference speed listed, mass about 460 g."
      },
      {
        "q": "What does C 2207 V mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 35 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2207-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (95/96 kN vs 83/80 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2207-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (95/96 kN vs 83/80 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×23 mm envelope as the SKF spherical roller bearing SKF 22207 E, but catalogue C/C0 differ (95/96 kN vs 88.8/85 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22207-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×23 mm envelope as the SKF spherical roller bearing SKF 22207 EK, but catalogue C/C0 differ (95/96 kN vs 88.8/85 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2207-V",
      "C 2207 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4908-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4908 V",
    "series": "C4900-series",
    "type": "carb_toroidal",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 100,
    "fatigue_load_limit_kN": 11.8,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 4908 V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 40 mm bore, 62 mm outside diameter, 22 mm wide unit rated 76.5 kN dynamic. SKF builds the CARB order number from size plus execution: the bare number C 4908 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 40 mm shaft deflects; no reference speed is listed and the limiting speed is 4,300 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 4,300 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 22 mm wide cavity does not fill itself.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 40 mm bore the small CARB executions are unusually wide (22 mm) for their 62 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4908 V must float; the two are designed to be used as a pair.",
      "Never use C 4908 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 40 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 76.5/100 kN ratings and 250 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4908 V have?",
        "a": "A C 4908 V measures 40 mm bore × 62 mm outside diameter × 22 mm width (1.575 × 2.441 × 0.866 in). From SKF catalogue PUB BU/P1 17000: dynamic C 76.5 kN, static C0 100 kN, fatigue limit Pu 11.8 kN, limiting speed 4,300 r/min, no reference speed listed, mass about 250 g."
      },
      {
        "q": "What does C 4908 V mean in SKF part numbering?",
        "a": "C marks CARB; 49 the dimension series; the size code gives 40 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4908 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4908-V",
      "C 4908 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2208-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2208 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 90,
    "static_load_kN": 86.5,
    "fatigue_load_limit_kN": 10.2,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 510,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2208 TN9 belongs to the CARB family — compact aligning roller bearings: envelope 40×80×23 mm, radial rating 90/86.5 kN C/C0, and no axial-locating function by design. The designation C 2208 TN9 separates into C (CARB), 22 (dimension series), 08 (40 mm bore) and TN9 (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage); envelope 40×80×23 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 40 mm shaft deflects; the 8,000 r/min reference and 11,000 r/min limiting speed are both catalogue values. The 510 g mass over the 40×80×23 mm envelope yields about 2.25 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: slide the bearing onto the 40 mm seat or heat it (max 120 °C) and seat it square; never press through the 23 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 40 mm bore the small CARB executions are unusually wide (23 mm) for their 80 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 90/86.5 kN ratings belong to this exact execution (C 2208 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2208 TN9 must float; the two are designed to be used as a pair.",
      "Never use C 2208 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 90/86.5 kN ratings and 510 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (90 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2208 TN9 is the cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage."
      },
      {
        "q": "How is C 2208 TN9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 40 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 23 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2208 TN9?",
        "a": "A C 2208 TN9 measures 40 mm bore × 80 mm outside diameter × 23 mm width (1.575 × 3.15 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 90 kN, static C0 86.5 kN, fatigue limit Pu 10.2 kN, reference speed 8,000 r/min, limiting speed 11,000 r/min, mass about 510 g."
      },
      {
        "q": "Can a CARB bearing like C 2208 TN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2208 TN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2208-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×80×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2208 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2208-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (90/86.5 kN vs 102/104 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22208",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×80×23 mm) SKF spherical roller bearing SKF 22208 E with ratings within 10 % — not a drop-in substitute: SKF 22208 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22208-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×80×23 mm) SKF spherical roller bearing SKF 22208 EK with ratings within 10 % — not a drop-in substitute: SKF 22208 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2208-TN9",
      "C 2208 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2208-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2208 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 90,
    "static_load_kN": 86.5,
    "fatigue_load_limit_kN": 10.2,
    "reference_speed_rpm": 8000,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 510,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2208 KTN9: the toroidal rollers allow the 40 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. The designation C 2208 KTN9 separates into C (CARB), 22 (dimension series), 08 (40 mm bore) and KTN9 (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage); envelope 40×80×23 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 40 mm shaft deflects; the 8,000 r/min reference and 11,000 r/min limiting speed are both catalogue values. The 510 g mass over the 40×80×23 mm envelope yields about 2.25 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 23 mm wide cavity does not fill itself.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 40 mm bore the small CARB executions are unusually wide (23 mm) for their 80 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 8,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 90/86.5 kN ratings belong to this exact execution (C 2208 KTN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2208 KTN9 must float; the two are designed to be used as a pair.",
      "The 90/86.5 kN ratings and 510 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2208 KTN9 mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2208 KTN9?",
        "a": "A C 2208 KTN9 measures 40 mm bore × 80 mm outside diameter × 23 mm width (1.575 × 3.15 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 90 kN, static C0 86.5 kN, fatigue limit Pu 10.2 kN, reference speed 8,000 r/min, limiting speed 11,000 r/min, mass about 510 g."
      },
      {
        "q": "Can a CARB bearing like C 2208 KTN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2208 KTN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2208 KTN9 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 08 = 40 mm bore (code 08 × 5); suffix KTN9 selects tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2208-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×80×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2208 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2208-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (90/86.5 kN vs 102/104 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22208",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×80×23 mm) SKF spherical roller bearing SKF 22208 E with ratings within 10 % — not a drop-in substitute: SKF 22208 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22208-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (40×80×23 mm) SKF spherical roller bearing SKF 22208 EK with ratings within 10 % — not a drop-in substitute: SKF 22208 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2208-KTN9",
      "C 2208 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2208-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2208 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 102,
    "static_load_kN": 104,
    "fatigue_load_limit_kN": 12.2,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2208 V in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. The designation C 2208 V separates into C (CARB), 22 (dimension series), 08 (40 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 40×80×23 mm follows the ISO 15 plan. The cylindrical 40 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 40×80×23 mm are identical — only the mounting method changes. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2208 V deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 40 mm bore the small CARB executions are unusually wide (23 mm) for their 80 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2208 V must float; the two are designed to be used as a pair.",
      "Never use C 2208 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 40 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 102/104 kN ratings and 530 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2208 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 40 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 23 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2208 V?",
        "a": "A C 2208 V measures 40 mm bore × 80 mm outside diameter × 23 mm width (1.575 × 3.15 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 102 kN, static C0 104 kN, fatigue limit Pu 12.2 kN, limiting speed 4,500 r/min, no reference speed listed, mass about 530 g."
      },
      {
        "q": "Can a CARB bearing like C 2208 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 2208 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2208 V designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 08 = 40 mm bore (code 08 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2208-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (102/104 kN vs 90/86.5 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2208-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (102/104 kN vs 90/86.5 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope as the SKF spherical roller bearing SKF 22208 E, but catalogue C/C0 differ (102/104 kN vs 98.5/90 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22208-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×23 mm envelope as the SKF spherical roller bearing SKF 22208 EK, but catalogue C/C0 differ (102/104 kN vs 98.5/90 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2208-V",
      "C 2208 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6909-V",
    "brand": "SKF",
    "manufacturer_designation": "C 6909 V",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 132,
    "static_load_kN": 200,
    "fatigue_load_limit_kN": 23.6,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 6909 V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 45×68×40 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 6909 V separates into C (CARB), 69 (dimension series), 09 (45 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 45×68×40 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 45 mm shaft deflects; no reference speed is listed and the limiting speed is 2,600 r/min. The 530 g mass over the 45×68×40 mm envelope yields about 2.93 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 68 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 45 mm bore the small CARB executions are unusually wide (40 mm) for their 68 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 132/200 kN ratings belong to this exact execution (C 6909 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 45 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Never use C 6909 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 132/200 kN ratings and 530 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 6909 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 45 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 40 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 6909 V?",
        "a": "A C 6909 V measures 45 mm bore × 68 mm outside diameter × 40 mm width (1.772 × 2.677 × 1.575 in). From SKF catalogue PUB BU/P1 17000: dynamic C 132 kN, static C0 200 kN, fatigue limit Pu 23.6 kN, limiting speed 2,600 r/min, no reference speed listed, mass about 530 g."
      },
      {
        "q": "Can a CARB bearing like C 6909 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 6909 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 6909 V designation read?",
        "a": "C = CARB toroidal family; 69 = dimension series; 09 = 45 mm bore (code 09 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6909-V",
      "C 6909 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2209-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2209 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 93,
    "static_load_kN": 93,
    "fatigue_load_limit_kN": 10.8,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2209 TN9 is the dimension series 22 CARB toroidal roller bearings member of the CARB range: 45 mm bore, 85 mm OD, 23 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. SKF builds the CARB order number from size plus execution: the bare number C 2209 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here TN9. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 45 mm shaft deflects; the 7,500 r/min reference and 11,000 r/min limiting speed are both catalogue values. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2209 TN9 deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 85 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 45 mm bore the small CARB executions are unusually wide (23 mm) for their 85 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 45 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 7,500 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 93/93 kN ratings belong to this exact execution (C 2209 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 93/93 kN ratings and 560 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2209 TN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2209 TN9 have?",
        "a": "A C 2209 TN9 measures 45 mm bore × 85 mm outside diameter × 23 mm width (1.772 × 3.346 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 93 kN, static C0 93 kN, fatigue limit Pu 10.8 kN, reference speed 7,500 r/min, limiting speed 11,000 r/min, mass about 560 g."
      },
      {
        "q": "What does C 2209 TN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 45 mm bore; TN9 is the execution (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2209-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×85×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2209 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2209-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (93/93 kN vs 106/110 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope as the SKF spherical roller bearing SKF 22209 E, but catalogue C/C0 differ (93/93 kN vs 104/98 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22209-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope as the SKF spherical roller bearing SKF 22209 EK, but catalogue C/C0 differ (93/93 kN vs 104/98 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2209-TN9",
      "C 2209 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2209-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2209 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 93,
    "static_load_kN": 93,
    "fatigue_load_limit_kN": 10.8,
    "reference_speed_rpm": 7500,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2209 KTN9 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 45 mm bore, 85 mm outside diameter, 23 mm wide unit rated 93 kN dynamic. The designation C 2209 KTN9 separates into C (CARB), 22 (dimension series), 09 (45 mm bore) and KTN9 (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage); envelope 45×85×23 mm follows the ISO 15 plan. The K suffix gives a 1:12 tapered 45 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 45×85×23 mm are identical — only the mounting method changes. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2209 KTN9 deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 85 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 45 mm bore the small CARB executions are unusually wide (23 mm) for their 85 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2209 KTN9 must float; the two are designed to be used as a pair.",
      "Never use C 2209 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 45 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 93/93 kN ratings and 560 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 2209 KTN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2209 KTN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2209 KTN9 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 09 = 45 mm bore (code 09 × 5); suffix KTN9 selects tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (93 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2209 KTN9 is the tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage."
      },
      {
        "q": "How is C 2209 KTN9 mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2209-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×85×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2209 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2209-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (93/93 kN vs 106/110 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope as the SKF spherical roller bearing SKF 22209 E, but catalogue C/C0 differ (93/93 kN vs 104/98 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22209-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope as the SKF spherical roller bearing SKF 22209 EK, but catalogue C/C0 differ (93/93 kN vs 104/98 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2209-KTN9",
      "C 2209 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2209-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2209 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 106,
    "static_load_kN": 110,
    "fatigue_load_limit_kN": 12.9,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 580,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2209 V: the toroidal rollers allow the 45 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. In C 2209 V the 22 dimension series fixes the 85 mm OD and 23 mm width around the 45 mm bore (code 09 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The V suffix denotes a full complement: the toroidal rollers fill the 23 mm space without a cage, raising C to 106 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2209 V deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 45 mm bore the small CARB executions are unusually wide (23 mm) for their 85 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 106/110 kN ratings belong to this exact execution (C 2209 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2209 V must float; the two are designed to be used as a pair.",
      "The 106/110 kN ratings and 580 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2209 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 45 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 23 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2209 V?",
        "a": "A C 2209 V measures 45 mm bore × 85 mm outside diameter × 23 mm width (1.772 × 3.346 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 106 kN, static C0 110 kN, fatigue limit Pu 12.9 kN, limiting speed 4,300 r/min, no reference speed listed, mass about 580 g."
      },
      {
        "q": "Can a CARB bearing like C 2209 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 2209 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2209 V designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 09 = 45 mm bore (code 09 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2209-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (106/110 kN vs 93/93 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2209-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (106/110 kN vs 93/93 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope as the SKF spherical roller bearing SKF 22209 E, but catalogue C/C0 differ (106/110 kN vs 104/98 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22209-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×23 mm envelope as the SKF spherical roller bearing SKF 22209 EK, but catalogue C/C0 differ (106/110 kN vs 104/98 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2209-V",
      "C 2209 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4910-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4910 V",
    "series": "C4900-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 86.5,
    "static_load_kN": 125,
    "fatigue_load_limit_kN": 14.6,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "weight_g": 290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4910 V in the dimension series 49 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. In C 4910 V the 49 dimension series fixes the 72 mm OD and 22 mm width around the 50 mm bore (code 10 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The cylindrical 50 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 50×72×22 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 22 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 50 mm seat or heat it (max 120 °C) and seat it square; never press through the 22 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (22 mm) for their 72 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4910 V must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 50 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 86.5/125 kN ratings and 290 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (86.5 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4910 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4910 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 50 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 22 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4910 V?",
        "a": "A C 4910 V measures 50 mm bore × 72 mm outside diameter × 22 mm width (1.969 × 2.835 × 0.866 in). From SKF catalogue PUB BU/P1 17000: dynamic C 86.5 kN, static C0 125 kN, fatigue limit Pu 14.6 kN, limiting speed 3,600 r/min, no reference speed listed, mass about 290 g."
      },
      {
        "q": "Can a CARB bearing like C 4910 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4910 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4910-V",
      "C 4910 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6910-V",
    "brand": "SKF",
    "manufacturer_designation": "C 6910 V",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 140,
    "static_load_kN": 224,
    "fatigue_load_limit_kN": 26,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 540,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 6910 V belongs to the CARB family — compact aligning roller bearings: envelope 50×72×40 mm, radial rating 140/224 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (69) identify the ISO dimension series and the last two (10) encode the 50 mm bore; suffixes describe bore and execution. The V suffix denotes a full complement: the toroidal rollers fill the 40 mm space without a cage, raising C to 140 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 40 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 50 mm seat or heat it (max 120 °C) and seat it square; never press through the 40 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (40 mm) for their 72 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 140/224 kN ratings belong to this exact execution (C 6910 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 6910 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 50 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 140/224 kN ratings and 540 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 6910 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 6910 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 6910 V have?",
        "a": "A C 6910 V measures 50 mm bore × 72 mm outside diameter × 40 mm width (1.969 × 2.835 × 1.575 in). From SKF catalogue PUB BU/P1 17000: dynamic C 140 kN, static C0 224 kN, fatigue limit Pu 26 kN, limiting speed 2,400 r/min, no reference speed listed, mass about 540 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6910-V",
      "C 6910 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4010-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 4010 TN9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 116,
    "static_load_kN": 140,
    "fatigue_load_limit_kN": 16.3,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4010 TN9 in the dimension series 40 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (10) encode the 50 mm bore; suffixes describe bore and execution. The TN9 suffix marks a glass fibre reinforced PA66 cage: lower friction and quieter than the full-complement V execution, with a 5,600 r/min reference speed, the usual choice for continuous-duty fans and paper rolls. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 30 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (30 mm) for their 80 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 116/140 kN ratings belong to this exact execution (C 4010 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4010 TN9 must float; the two are designed to be used as a pair.",
      "Never use C 4010 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 116/140 kN ratings and 550 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 4010 TN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4010 TN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4010 TN9 have?",
        "a": "A C 4010 TN9 measures 50 mm bore × 80 mm outside diameter × 30 mm width (1.969 × 3.15 × 1.181 in). From SKF catalogue PUB BU/P1 17000: dynamic C 116 kN, static C0 140 kN, fatigue limit Pu 16.3 kN, reference speed 5,600 r/min, limiting speed 7,500 r/min, mass about 550 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4010-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×30 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (116/140 kN vs 137/176 kN) — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4010-TN9",
      "C 4010 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4010-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4010 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 137,
    "static_load_kN": 176,
    "fatigue_load_limit_kN": 20.8,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "weight_g": 580,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4010 V is the dimension series 40 CARB toroidal roller bearings member of the CARB range: 50 mm bore, 80 mm OD, 30 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. SKF builds the CARB order number from size plus execution: the bare number C 4010 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The V suffix denotes a full complement: the toroidal rollers fill the 30 mm space without a cage, raising C to 137 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 3,000 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: slide the bearing onto the 50 mm seat or heat it (max 120 °C) and seat it square; never press through the 30 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (30 mm) for their 80 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4010 V must float; the two are designed to be used as a pair.",
      "Never use C 4010 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 50 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 137/176 kN ratings and 580 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4010 V have?",
        "a": "A C 4010 V measures 50 mm bore × 80 mm outside diameter × 30 mm width (1.969 × 3.15 × 1.181 in). From SKF catalogue PUB BU/P1 17000: dynamic C 137 kN, static C0 176 kN, fatigue limit Pu 20.8 kN, limiting speed 3,000 r/min, no reference speed listed, mass about 580 g."
      },
      {
        "q": "What does C 4010 V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 50 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4010 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4010 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4010-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×30 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (137/176 kN vs 116/140 kN) — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4010-V",
      "C 4010 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2210-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2210 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 98,
    "static_load_kN": 100,
    "fatigue_load_limit_kN": 11.8,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 9500,
    "max_rpm": 9500,
    "weight_g": 600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2210 TN9 in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. The designation C 2210 TN9 separates into C (CARB), 22 (dimension series), 10 (50 mm bore) and TN9 (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage); envelope 50×90×23 mm follows the ISO 15 plan. The cylindrical 50 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 50×90×23 mm are identical — only the mounting method changes. Selection arithmetic: C 98 kN against C0 100 kN gives a C0/C ratio of 1.02, and the 11.8 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 90 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (23 mm) for their 90 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2210 TN9 must float; the two are designed to be used as a pair.",
      "The quoted 98/100 kN ratings belong to this exact execution (C 2210 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2210 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 98/100 kN ratings and 600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (98 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2210 TN9 is the cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage."
      },
      {
        "q": "How is C 2210 TN9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 50 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 23 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2210 TN9?",
        "a": "A C 2210 TN9 measures 50 mm bore × 90 mm outside diameter × 23 mm width (1.969 × 3.543 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 98 kN, static C0 100 kN, fatigue limit Pu 11.8 kN, reference speed 7,000 r/min, limiting speed 9,500 r/min, mass about 600 g."
      },
      {
        "q": "Can a CARB bearing like C 2210 TN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2210 TN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2210-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2210 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2210-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (98/100 kN vs 114/122 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22210",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×90×23 mm) SKF spherical roller bearing SKF 22210 E with ratings within 10 % — not a drop-in substitute: SKF 22210 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22210-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×90×23 mm) SKF spherical roller bearing SKF 22210 EK with ratings within 10 % — not a drop-in substitute: SKF 22210 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2210-TN9",
      "C 2210 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2210-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2210 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 98,
    "static_load_kN": 100,
    "fatigue_load_limit_kN": 11.8,
    "reference_speed_rpm": 7000,
    "limiting_speed_rpm": 9500,
    "max_rpm": 9500,
    "weight_g": 600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2210 KTN9 is the dimension series 22 CARB toroidal roller bearings member of the CARB range: 50 mm bore, 90 mm OD, 23 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (10) encode the 50 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 50 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2210 KTN9 deliberately carries none. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 23 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (23 mm) for their 90 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2210 KTN9 must float; the two are designed to be used as a pair.",
      "Never use C 2210 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 50 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 7,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 98/100 kN ratings and 600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 2210 KTN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 50 mm bore; KTN9 is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2210 KTN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2210 KTN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2210-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×23 mm ISO 15 envelope and equivalent catalogue C/C0; C 2210 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2210-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (98/100 kN vs 114/122 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22210",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×90×23 mm) SKF spherical roller bearing SKF 22210 E with ratings within 10 % — not a drop-in substitute: SKF 22210 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22210-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (50×90×23 mm) SKF spherical roller bearing SKF 22210 EK with ratings within 10 % — not a drop-in substitute: SKF 22210 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2210-KTN9",
      "C 2210 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2210-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2210 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 114,
    "static_load_kN": 122,
    "fatigue_load_limit_kN": 14.3,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2210 V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 50 mm bore, 90 mm outside diameter, 23 mm wide unit rated 114 kN dynamic. SKF builds the CARB order number from size plus execution: the bare number C 2210 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The cylindrical 50 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 50×90×23 mm are identical — only the mounting method changes. Selection arithmetic: C 114 kN against C0 122 kN gives a C0/C ratio of 1.07, and the 14.3 kN fatigue load limit Pu sets the contamination-adjusted life floor. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 23 mm wide cavity does not fill itself.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 50 mm bore the small CARB executions are unusually wide (23 mm) for their 90 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 114/122 kN ratings belong to this exact execution (C 2210 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2210 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 50 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 114/122 kN ratings and 630 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 2210 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2210 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2210 V have?",
        "a": "A C 2210 V measures 50 mm bore × 90 mm outside diameter × 23 mm width (1.969 × 3.543 × 0.906 in). From SKF catalogue PUB BU/P1 17000: dynamic C 114 kN, static C0 122 kN, fatigue limit Pu 14.3 kN, limiting speed 3,800 r/min, no reference speed listed, mass about 630 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2210-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (114/122 kN vs 98/100 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2210-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (114/122 kN vs 98/100 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope as the SKF spherical roller bearing SKF 22210 E, but catalogue C/C0 differ (114/122 kN vs 107/108 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22210-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×23 mm envelope as the SKF spherical roller bearing SKF 22210 EK, but catalogue C/C0 differ (114/122 kN vs 107/108 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2210-V",
      "C 2210 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6911-V",
    "brand": "SKF",
    "manufacturer_designation": "C 6911 V",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 180,
    "static_load_kN": 300,
    "fatigue_load_limit_kN": 35.5,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 6911 V in the dimension series 69 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. In C 6911 V the 69 dimension series fixes the 80 mm OD and 45 mm width around the 55 mm bore (code 11 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 55 mm shaft deflects; no reference speed is listed and the limiting speed is 2,200 r/min. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 6911 V deliberately carries none. Mounting: slide the bearing onto the 55 mm seat or heat it (max 120 °C) and seat it square; never press through the 45 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 55 mm bore the small CARB executions are unusually wide (45 mm) for their 80 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 180/300 kN ratings belong to this exact execution (C 6911 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 6911 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 180/300 kN ratings and 780 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 6911 V designation read?",
        "a": "C = CARB toroidal family; 69 = dimension series; 11 = 55 mm bore (code 11 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (180 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 6911 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 6911 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 55 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 45 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 6911 V?",
        "a": "A C 6911 V measures 55 mm bore × 80 mm outside diameter × 45 mm width (2.165 × 3.15 × 1.772 in). From SKF catalogue PUB BU/P1 17000: dynamic C 180 kN, static C0 300 kN, fatigue limit Pu 35.5 kN, limiting speed 2,200 r/min, no reference speed listed, mass about 780 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6911-V",
      "C 6911 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2211-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2211 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 116,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 13.4,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 9000,
    "max_rpm": 9000,
    "weight_g": 800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2211 TN9 denotes a toroidal roller bearing whose 25 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 2211 TN9 separates into C (CARB), 22 (dimension series), 11 (55 mm bore) and TN9 (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage); envelope 55×100×25 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 55 mm seat. The 800 g mass over the 55×100×25 mm envelope yields about 2.11 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 55 mm bore the small CARB executions are unusually wide (25 mm) for their 100 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 6,300 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 116/114 kN ratings belong to this exact execution (C 2211 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2211 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 55 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 116/114 kN ratings and 800 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2211 TN9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 55 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 25 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2211 TN9?",
        "a": "A C 2211 TN9 measures 55 mm bore × 100 mm outside diameter × 25 mm width (2.165 × 3.937 × 0.984 in). From SKF catalogue PUB BU/P1 17000: dynamic C 116 kN, static C0 114 kN, fatigue limit Pu 13.4 kN, reference speed 6,300 r/min, limiting speed 9,000 r/min, mass about 800 g."
      },
      {
        "q": "Can a CARB bearing like C 2211 TN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2211 TN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2211 TN9 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 11 = 55 mm bore (code 11 × 5); suffix TN9 selects cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2211-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×25 mm ISO 15 envelope and equivalent catalogue C/C0; C 2211 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2211-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (116/114 kN vs 132/134 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2211-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and 1:12 tapered-bore K full-complement V executions (116/114 kN vs 132/134 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope as the SKF spherical roller bearing SKF 22211 E, but catalogue C/C0 differ (116/114 kN vs 129/127 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22211-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope as the SKF spherical roller bearing SKF 22211 EK, but catalogue C/C0 differ (116/114 kN vs 129/127 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2211-TN9",
      "C 2211 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2211-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2211 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 116,
    "static_load_kN": 114,
    "fatigue_load_limit_kN": 13.4,
    "reference_speed_rpm": 6300,
    "limiting_speed_rpm": 9000,
    "max_rpm": 9000,
    "weight_g": 800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2211 KTN9 denotes a toroidal roller bearing whose 25 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 2211 KTN9 separates into C (CARB), 22 (dimension series), 11 (55 mm bore) and KTN9 (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage); envelope 55×100×25 mm follows the ISO 15 plan. The TN9 suffix marks a glass fibre reinforced PA66 cage: lower friction and quieter than the full-complement V execution, with a 6,300 r/min reference speed, the usual choice for continuous-duty fans and paper rolls. The 800 g mass over the 55×100×25 mm envelope yields about 2.11 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 25 mm wide cavity does not fill itself.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 55 mm bore the small CARB executions are unusually wide (25 mm) for their 100 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 6,300 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 116/114 kN ratings belong to this exact execution (C 2211 KTN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2211 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 55 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 116/114 kN ratings and 800 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (116 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2211 KTN9 is the tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage."
      },
      {
        "q": "How is C 2211 KTN9 mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2211 KTN9?",
        "a": "A C 2211 KTN9 measures 55 mm bore × 100 mm outside diameter × 25 mm width (2.165 × 3.937 × 0.984 in). From SKF catalogue PUB BU/P1 17000: dynamic C 116 kN, static C0 114 kN, fatigue limit Pu 13.4 kN, reference speed 6,300 r/min, limiting speed 9,000 r/min, mass about 800 g."
      },
      {
        "q": "Can a CARB bearing like C 2211 KTN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2211 KTN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2211-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×25 mm ISO 15 envelope and equivalent catalogue C/C0; C 2211 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2211-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (116/114 kN vs 132/134 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2211-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and 1:12 tapered-bore K full-complement V executions (116/114 kN vs 132/134 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope as the SKF spherical roller bearing SKF 22211 E, but catalogue C/C0 differ (116/114 kN vs 129/127 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22211-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope as the SKF spherical roller bearing SKF 22211 EK, but catalogue C/C0 differ (116/114 kN vs 129/127 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2211-KTN9",
      "C 2211 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2211-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2211 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 132,
    "static_load_kN": 134,
    "fatigue_load_limit_kN": 15.6,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "weight_g": 820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2211 V is the dimension series 22 CARB toroidal roller bearings member of the CARB range: 55 mm bore, 100 mm OD, 25 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 2211 V separates into C (CARB), 22 (dimension series), 11 (55 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 55×100×25 mm follows the ISO 15 plan. The V suffix denotes a full complement: the toroidal rollers fill the 25 mm space without a cage, raising C to 132 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 3,400 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 25 mm wide cavity does not fill itself.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 55 mm bore the small CARB executions are unusually wide (25 mm) for their 100 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 132/134 kN ratings belong to this exact execution (C 2211 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2211 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 55 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 132/134 kN ratings and 820 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 2211 V designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 11 = 55 mm bore (code 11 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (132 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2211 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 2211 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 55 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 25 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2211 V?",
        "a": "A C 2211 V measures 55 mm bore × 100 mm outside diameter × 25 mm width (2.165 × 3.937 × 0.984 in). From SKF catalogue PUB BU/P1 17000: dynamic C 132 kN, static C0 134 kN, fatigue limit Pu 15.6 kN, limiting speed 3,400 r/min, no reference speed listed, mass about 820 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2211-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (132/134 kN vs 116/114 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2211-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (132/134 kN vs 116/114 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2211-KV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×25 mm ISO 15 envelope and equivalent catalogue C/C0; C 2211 KV is the 1:12 tapered-bore K full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22211",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (55×100×25 mm) SKF spherical roller bearing SKF 22211 E with ratings within 10 % — not a drop-in substitute: SKF 22211 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22211-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (55×100×25 mm) SKF spherical roller bearing SKF 22211 EK with ratings within 10 % — not a drop-in substitute: SKF 22211 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2211-V",
      "C 2211 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2211-KV",
    "brand": "SKF",
    "manufacturer_designation": "C 2211 KV",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 132,
    "static_load_kN": 134,
    "fatigue_load_limit_kN": 15.6,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "weight_g": 820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2211 KV: the toroidal rollers allow the 55 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. SKF builds the CARB order number from size plus execution: the bare number C 2211 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KV. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 55 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2211 KV deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 55 mm bore the small CARB executions are unusually wide (25 mm) for their 100 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 55 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 132/134 kN ratings belong to this exact execution (C 2211 KV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2211 KV as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 132/134 kN ratings and 820 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2211 KV have?",
        "a": "A C 2211 KV measures 55 mm bore × 100 mm outside diameter × 25 mm width (2.165 × 3.937 × 0.984 in). From SKF catalogue PUB BU/P1 17000: dynamic C 132 kN, static C0 134 kN, fatigue limit Pu 15.6 kN, limiting speed 3,400 r/min, no reference speed listed, mass about 820 g."
      },
      {
        "q": "What does C 2211 KV mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 55 mm bore; KV is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2211 KV used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2211 KV sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2211-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and cylindrical-bore TN9 PA66-caged executions (132/134 kN vs 116/114 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2211-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×25 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (132/134 kN vs 116/114 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2211-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×25 mm ISO 15 envelope and equivalent catalogue C/C0; C 2211 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22211",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (55×100×25 mm) SKF spherical roller bearing SKF 22211 E with ratings within 10 % — not a drop-in substitute: SKF 22211 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22211-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (55×100×25 mm) SKF spherical roller bearing SKF 22211 EK with ratings within 10 % — not a drop-in substitute: SKF 22211 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2211-KV",
      "C 2211 KV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6912-2NSV",
    "brand": "SKF",
    "manufacturer_designation": "C 6912-2NSV",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 190,
    "static_load_kN": 335,
    "fatigue_load_limit_kN": 39,
    "weight_g": 830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 6912-2NSV is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 60×85×45 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. SKF builds the CARB order number from size plus execution: the bare number C 6912 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here 2NSV. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 60 mm seat. Selection arithmetic: C 190 kN against C0 335 kN gives a C0/C ratio of 1.76, and the 39 kN fatigue load limit Pu sets the contamination-adjusted life floor. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 60 mm bore the small CARB executions are unusually wide (45 mm) for their 85 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 190/335 kN ratings belong to this exact execution (C 6912-2NSV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 6912-2NSV as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 60 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 190/335 kN ratings and 830 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 6912-2NSV sealed?",
        "a": "Yes — this is a sealed full-complement execution (2NSV nitrile seals), greased at the factory; the catalogue lists no reference speed or limiting speed."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 6912-2NSV have?",
        "a": "A C 6912-2NSV measures 60 mm bore × 85 mm outside diameter × 45 mm width (2.362 × 3.346 × 1.772 in). From SKF catalogue PUB BU/P1 17000: dynamic C 190 kN, static C0 335 kN, fatigue limit Pu 39 kN, no reference or limiting speeds are listed (sealed, grease-filled execution), mass about 830 g."
      },
      {
        "q": "What does C 6912-2NSV mean in SKF part numbering?",
        "a": "C marks CARB; 69 the dimension series; the size code gives 60 mm bore; 2NSV is the execution (cylindrical bore for direct shaft fitting, 2NSV sealed full-complement execution). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6912-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×85×45 mm ISO 15 envelope and equivalent catalogue C/C0; C 6912 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6912-2NSV",
      "C 6912-2NSV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6912-V",
    "brand": "SKF",
    "manufacturer_designation": "C 6912 V",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 190,
    "static_load_kN": 335,
    "fatigue_load_limit_kN": 39,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "weight_g": 830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 6912 V: the toroidal rollers allow the 60 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. SKF builds the CARB order number from size plus execution: the bare number C 6912 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 60 mm shaft deflects; no reference speed is listed and the limiting speed is 1,900 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 1,900 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 60 mm bore the small CARB executions are unusually wide (45 mm) for their 85 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 60 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 6912 V must float; the two are designed to be used as a pair.",
      "The 190/335 kN ratings and 830 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 6912 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 6912 V have?",
        "a": "A C 6912 V measures 60 mm bore × 85 mm outside diameter × 45 mm width (2.362 × 3.346 × 1.772 in). From SKF catalogue PUB BU/P1 17000: dynamic C 190 kN, static C0 335 kN, fatigue limit Pu 39 kN, limiting speed 1,900 r/min, no reference speed listed, mass about 830 g."
      },
      {
        "q": "What does C 6912 V mean in SKF part numbering?",
        "a": "C marks CARB; 69 the dimension series; the size code gives 60 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6912-2NSV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×85×45 mm ISO 15 envelope and equivalent catalogue C/C0; C 6912-2NSV is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6912-V",
      "C 6912 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2212-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2212 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 143,
    "static_load_kN": 156,
    "fatigue_load_limit_kN": 18.3,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2212 TN9: the toroidal rollers allow the 60 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. SKF builds the CARB order number from size plus execution: the bare number C 2212 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here TN9. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 60 mm shaft deflects; the 5,600 r/min reference and 7,500 r/min limiting speed are both catalogue values. Selection arithmetic: C 143 kN against C0 156 kN gives a C0/C ratio of 1.09, and the 18.3 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: slide the bearing onto the 60 mm seat or heat it (max 120 °C) and seat it square; never press through the 28 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 60 mm bore the small CARB executions are unusually wide (28 mm) for their 110 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 60 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 5,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 2212 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 143/156 kN ratings belong to this exact execution (C 2212 TN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 143/156 kN ratings and 1100 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2212 TN9 have?",
        "a": "A C 2212 TN9 measures 60 mm bore × 110 mm outside diameter × 28 mm width (2.362 × 4.331 × 1.102 in). From SKF catalogue PUB BU/P1 17000: dynamic C 143 kN, static C0 156 kN, fatigue limit Pu 18.3 kN, reference speed 5,600 r/min, limiting speed 7,500 r/min, mass about 1100 g."
      },
      {
        "q": "What does C 2212 TN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 60 mm bore; TN9 is the execution (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2212 TN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2212 TN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2212-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×28 mm ISO 15 envelope and equivalent catalogue C/C0; C 2212 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2212-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (143/156 kN vs 166/190 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2212-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and 1:12 tapered-bore K full-complement V executions (143/156 kN vs 166/190 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 E, but catalogue C/C0 differ (143/156 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22212-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 EK, but catalogue C/C0 differ (143/156 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2212-TN9",
      "C 2212 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2212-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2212 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 143,
    "static_load_kN": 156,
    "fatigue_load_limit_kN": 18.3,
    "reference_speed_rpm": 5600,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2212 KTN9 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 60×110×28 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 2212 KTN9 separates into C (CARB), 22 (dimension series), 12 (60 mm bore) and KTN9 (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage); envelope 60×110×28 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 60 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2212 KTN9 deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 110 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 60 mm bore the small CARB executions are unusually wide (28 mm) for their 110 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2212 KTN9 must float; the two are designed to be used as a pair.",
      "The quoted 143/156 kN ratings belong to this exact execution (C 2212 KTN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2212 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 143/156 kN ratings and 1100 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2212 KTN9?",
        "a": "A C 2212 KTN9 measures 60 mm bore × 110 mm outside diameter × 28 mm width (2.362 × 4.331 × 1.102 in). From SKF catalogue PUB BU/P1 17000: dynamic C 143 kN, static C0 156 kN, fatigue limit Pu 18.3 kN, reference speed 5,600 r/min, limiting speed 7,500 r/min, mass about 1100 g."
      },
      {
        "q": "Can a CARB bearing like C 2212 KTN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2212 KTN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2212 KTN9 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 12 = 60 mm bore (code 12 × 5); suffix KTN9 selects tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (143 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2212 KTN9 is the tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2212-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×28 mm ISO 15 envelope and equivalent catalogue C/C0; C 2212 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2212-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (143/156 kN vs 166/190 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2212-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and 1:12 tapered-bore K full-complement V executions (143/156 kN vs 166/190 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 E, but catalogue C/C0 differ (143/156 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22212-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 EK, but catalogue C/C0 differ (143/156 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2212-KTN9",
      "C 2212 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2212-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2212 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 166,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 22.4,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 1150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2212 V denotes a toroidal roller bearing whose 28 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (12) encode the 60 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 60 mm shaft deflects; no reference speed is listed and the limiting speed is 2,800 r/min. The 1150 g mass over the 60×110×28 mm envelope yields about 2.77 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 28 mm wide cavity does not fill itself.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 60 mm bore the small CARB executions are unusually wide (28 mm) for their 110 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 60 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 2212 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 166/190 kN ratings belong to this exact execution (C 2212 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 166/190 kN ratings and 1150 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 2212 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2212 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2212 V have?",
        "a": "A C 2212 V measures 60 mm bore × 110 mm outside diameter × 28 mm width (2.362 × 4.331 × 1.102 in). From SKF catalogue PUB BU/P1 17000: dynamic C 166 kN, static C0 190 kN, fatigue limit Pu 22.4 kN, limiting speed 2,800 r/min, no reference speed listed, mass about 1150 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2212-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (166/190 kN vs 143/156 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2212-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (166/190 kN vs 143/156 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2212-KV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×28 mm ISO 15 envelope and equivalent catalogue C/C0; C 2212 KV is the 1:12 tapered-bore K full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 E, but catalogue C/C0 differ (166/190 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22212-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 EK, but catalogue C/C0 differ (166/190 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2212-V",
      "C 2212 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2212-KV",
    "brand": "SKF",
    "manufacturer_designation": "C 2212 KV",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 166,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 22.4,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 1150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2212 KV: the toroidal rollers allow the 60 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. SKF builds the CARB order number from size plus execution: the bare number C 2212 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KV. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 60 mm shaft deflects; no reference speed is listed and the limiting speed is 2,800 r/min. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2212 KV deliberately carries none. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 28 mm wide cavity does not fill itself.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 60 mm bore the small CARB executions are unusually wide (28 mm) for their 110 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 166/190 kN ratings belong to this exact execution (C 2212 KV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2212 KV as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 60 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 166/190 kN ratings and 1150 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2212 KV have?",
        "a": "A C 2212 KV measures 60 mm bore × 110 mm outside diameter × 28 mm width (2.362 × 4.331 × 1.102 in). From SKF catalogue PUB BU/P1 17000: dynamic C 166 kN, static C0 190 kN, fatigue limit Pu 22.4 kN, limiting speed 2,800 r/min, no reference speed listed, mass about 1150 g."
      },
      {
        "q": "What does C 2212 KV mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 60 mm bore; KV is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2212 KV used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2212 KV sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2212-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and cylindrical-bore TN9 PA66-caged executions (166/190 kN vs 143/156 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2212-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (166/190 kN vs 143/156 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2212-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×28 mm ISO 15 envelope and equivalent catalogue C/C0; C 2212 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 E, but catalogue C/C0 differ (166/190 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22212-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×28 mm envelope as the SKF spherical roller bearing SKF 22212 EK, but catalogue C/C0 differ (166/190 kN vs 159/166 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2212-KV",
      "C 2212 KV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4013-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4013-2CS5V/GEM9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 102,
    "static_load_kN": 173,
    "fatigue_load_limit_kN": 20.4,
    "limiting_speed_rpm": 150,
    "max_rpm": 150,
    "weight_g": 1050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4013-2CS5V/GEM9 belongs to the CARB family — compact aligning roller bearings: envelope 65×100×35 mm, radial rating 102/173 kN C/C0, and no axial-locating function by design. In C 4013-2CS5V/GEM9 the 40 dimension series fixes the 100 mm OD and 35 mm width around the 65 mm bore (the bore is written directly after the slash (no bore code)); the suffix 2CS5V/GEM9 then selects the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. The 2CS5V/GEM9 execution adds nitrile contact seals on both sides plus an annular-groove relubrication feature and a high-viscosity grease fill; the full-complement rollers keep 102 kN dynamic at a reduced 150 r/min ceiling. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 35 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 65 mm bore the small CARB executions are unusually wide (35 mm) for their 100 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 102/173 kN ratings belong to this exact execution (C 4013-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4013-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 65 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 102/173 kN ratings and 1050 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 4013-2CS5V/GEM9 designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 65 mm (slash-size) = 65 mm bore (the bore is written directly after the slash (no bore code)); suffix 2CS5V/GEM9 selects cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (102 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4013-2CS5V/GEM9 is the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove."
      },
      {
        "q": "How is C 4013-2CS5V/GEM9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 65 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 35 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4013-2CS5V/GEM9?",
        "a": "A C 4013-2CS5V/GEM9 measures 65 mm bore × 100 mm outside diameter × 35 mm width (2.559 × 3.937 × 1.378 in). From SKF catalogue PUB BU/P1 17000: dynamic C 102 kN, static C0 173 kN, fatigue limit Pu 20.4 kN, limiting speed 150 r/min, no reference speed listed, mass about 1050 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24013",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×35 mm envelope as the SKF spherical roller bearing SKF 24013 CC/W33, but catalogue C/C0 differ (102/173 kN vs 137/173 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4013-2CS5V-GEM9",
      "C 4013-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2213-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2213 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 180,
    "static_load_kN": 180,
    "fatigue_load_limit_kN": 21.2,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 1450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2213 TN9 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 65×120×31 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. SKF builds the CARB order number from size plus execution: the bare number C 2213 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here TN9. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 65 mm shaft deflects; the 5,300 r/min reference and 7,500 r/min limiting speed are both catalogue values. Speed planning separates the 5,300 r/min thermal reference from the 7,500 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the TN9-caged executions run faster and cooler at light load. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 120 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 65 mm bore the small CARB executions are unusually wide (31 mm) for their 120 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2213 TN9 must float; the two are designed to be used as a pair.",
      "Never use C 2213 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 65 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 5,300 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 180/180 kN ratings and 1450 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2213 TN9 have?",
        "a": "A C 2213 TN9 measures 65 mm bore × 120 mm outside diameter × 31 mm width (2.559 × 4.724 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 180 kN, static C0 180 kN, fatigue limit Pu 21.2 kN, reference speed 5,300 r/min, limiting speed 7,500 r/min, mass about 1450 g."
      },
      {
        "q": "What does C 2213 TN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 65 mm bore; TN9 is the execution (cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2213 TN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2213 TN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2213-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2213 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2213-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (180/180 kN vs 204/216 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2213-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and 1:12 tapered-bore K full-complement V executions (180/180 kN vs 204/216 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope as the SKF spherical roller bearing SKF 22213 E, but catalogue C/C0 differ (180/180 kN vs 198/216 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22213-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope as the SKF spherical roller bearing SKF 22213 EK, but catalogue C/C0 differ (180/180 kN vs 198/216 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2213-TN9",
      "C 2213 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2213-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2213 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 180,
    "static_load_kN": 180,
    "fatigue_load_limit_kN": 21.2,
    "reference_speed_rpm": 5300,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 1450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2213 KTN9 belongs to the CARB family — compact aligning roller bearings: envelope 65×120×31 mm, radial rating 180/180 kN C/C0, and no axial-locating function by design. SKF builds the CARB order number from size plus execution: the bare number C 2213 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KTN9. The K suffix gives a 1:12 tapered 65 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 65×120×31 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 31 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 120 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 65 mm bore the small CARB executions are unusually wide (31 mm) for their 120 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 65 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 5,300 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2213 KTN9 must float; the two are designed to be used as a pair.",
      "Never use C 2213 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 180/180 kN ratings and 1450 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2213 KTN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2213 KTN9 have?",
        "a": "A C 2213 KTN9 measures 65 mm bore × 120 mm outside diameter × 31 mm width (2.559 × 4.724 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 180 kN, static C0 180 kN, fatigue limit Pu 21.2 kN, reference speed 5,300 r/min, limiting speed 7,500 r/min, mass about 1450 g."
      },
      {
        "q": "What does C 2213 KTN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 65 mm bore; KTN9 is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2213-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2213 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2213-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (180/180 kN vs 204/216 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2213-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and 1:12 tapered-bore K full-complement V executions (180/180 kN vs 204/216 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope as the SKF spherical roller bearing SKF 22213 E, but catalogue C/C0 differ (180/180 kN vs 198/216 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22213-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope as the SKF spherical roller bearing SKF 22213 EK, but catalogue C/C0 differ (180/180 kN vs 198/216 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2213-KTN9",
      "C 2213 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2213-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2213 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 204,
    "static_load_kN": 216,
    "fatigue_load_limit_kN": 25.5,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2213 V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 65×120×31 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. SKF builds the CARB order number from size plus execution: the bare number C 2213 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 65 mm seat. The 1500 g mass over the 65×120×31 mm envelope yields about 3.14 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 31 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 65 mm bore the small CARB executions are unusually wide (31 mm) for their 120 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2213 V must float; the two are designed to be used as a pair.",
      "Never use C 2213 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 65 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 204/216 kN ratings and 1500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 2213 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2213 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2213 V have?",
        "a": "A C 2213 V measures 65 mm bore × 120 mm outside diameter × 31 mm width (2.559 × 4.724 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 204 kN, static C0 216 kN, fatigue limit Pu 25.5 kN, limiting speed 2,400 r/min, no reference speed listed, mass about 1500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2213-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (204/216 kN vs 180/180 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2213-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (204/216 kN vs 180/180 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2213-KV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2213 KV is the 1:12 tapered-bore K full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22213",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (65×120×31 mm) SKF spherical roller bearing SKF 22213 E with ratings within 10 % — not a drop-in substitute: SKF 22213 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22213-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (65×120×31 mm) SKF spherical roller bearing SKF 22213 EK with ratings within 10 % — not a drop-in substitute: SKF 22213 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2213-V",
      "C 2213 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2213-KV",
    "brand": "SKF",
    "manufacturer_designation": "C 2213 KV",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 204,
    "static_load_kN": 216,
    "fatigue_load_limit_kN": 25.5,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2213 KV denotes a toroidal roller bearing whose 31 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 2213 KV separates into C (CARB), 22 (dimension series), 13 (65 mm bore) and KV (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)); envelope 65×120×31 mm follows the ISO 15 plan. The K suffix gives a 1:12 tapered 65 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 65×120×31 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 31 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 31 mm wide cavity does not fill itself.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 65 mm bore the small CARB executions are unusually wide (31 mm) for their 120 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2213 KV must float; the two are designed to be used as a pair.",
      "Never use C 2213 KV as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 65 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 204/216 kN ratings and 1500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2213 KV?",
        "a": "A C 2213 KV measures 65 mm bore × 120 mm outside diameter × 31 mm width (2.559 × 4.724 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 204 kN, static C0 216 kN, fatigue limit Pu 25.5 kN, limiting speed 2,400 r/min, no reference speed listed, mass about 1500 g."
      },
      {
        "q": "Can a CARB bearing like C 2213 KV locate the shaft axially?",
        "a": "No — that is the defining feature. C 2213 KV deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2213 KV designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 13 = 65 mm bore (code 13 × 5); suffix KV selects tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (204 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2213 KV is the tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2213-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and cylindrical-bore TN9 PA66-caged executions (204/216 kN vs 180/180 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2213-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (204/216 kN vs 180/180 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2213-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2213 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22213",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (65×120×31 mm) SKF spherical roller bearing SKF 22213 E with ratings within 10 % — not a drop-in substitute: SKF 22213 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22213-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (65×120×31 mm) SKF spherical roller bearing SKF 22213 EK with ratings within 10 % — not a drop-in substitute: SKF 22213 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2213-KV",
      "C 2213 KV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2214-TN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2214 TN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 186,
    "static_load_kN": 196,
    "fatigue_load_limit_kN": 22.8,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2214 TN9 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 70 mm bore, 125 mm outside diameter, 31 mm wide unit rated 186 kN dynamic. In C 2214 TN9 the 22 dimension series fixes the 125 mm OD and 31 mm width around the 70 mm bore (code 14 × 5); the suffix TN9 then selects the cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage. The TN9 suffix marks a glass fibre reinforced PA66 cage: lower friction and quieter than the full-complement V execution, with a 5,000 r/min reference speed, the usual choice for continuous-duty fans and paper rolls. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2214 TN9 deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 70 mm bore the small CARB executions are unusually wide (31 mm) for their 125 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2214 TN9 must float; the two are designed to be used as a pair.",
      "Never use C 2214 TN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 70 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 186/196 kN ratings and 1500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 2214 TN9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2214 TN9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2214 TN9 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 14 = 70 mm bore (code 14 × 5); suffix TN9 selects cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (186 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2214 TN9 is the cylindrical bore for direct shaft fitting, TN9 glass-fibre PA66 cage."
      },
      {
        "q": "How is C 2214 TN9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 70 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 31 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2214-KTN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 70×125×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2214 KTN9 is the 1:12 tapered-bore K TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2214-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore TN9 PA66-caged and cylindrical-bore full-complement V executions (186/196 kN vs 212/228 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22214",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope as the SKF spherical roller bearing SKF 22214 E, but catalogue C/C0 differ (186/196 kN vs 213/228 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22214-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope as the SKF spherical roller bearing SKF 22214 EK, but catalogue C/C0 differ (186/196 kN vs 213/228 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2214-TN9",
      "C 2214 TN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2214-KTN9",
    "brand": "SKF",
    "manufacturer_designation": "C 2214 KTN9",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "polymer_PA66",
    "dynamic_load_kN": 186,
    "static_load_kN": 196,
    "fatigue_load_limit_kN": 22.8,
    "reference_speed_rpm": 5000,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 1500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2214 KTN9 in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. SKF builds the CARB order number from size plus execution: the bare number C 2214 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KTN9. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 70 mm shaft deflects; the 5,000 r/min reference and 7,000 r/min limiting speed are both catalogue values. Selection arithmetic: C 186 kN against C0 196 kN gives a C0/C ratio of 1.05, and the 22.8 kN fatigue load limit Pu sets the contamination-adjusted life floor. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 70 mm bore the small CARB executions are unusually wide (31 mm) for their 125 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 186/196 kN ratings belong to this exact execution (C 2214 KTN9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2214 KTN9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 70 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 186/196 kN ratings and 1500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2214 KTN9 have?",
        "a": "A C 2214 KTN9 measures 70 mm bore × 125 mm outside diameter × 31 mm width (2.756 × 4.921 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 186 kN, static C0 196 kN, fatigue limit Pu 22.8 kN, reference speed 5,000 r/min, limiting speed 7,000 r/min, mass about 1500 g."
      },
      {
        "q": "What does C 2214 KTN9 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 70 mm bore; KTN9 is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, TN9 glass-fibre PA66 cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2214 KTN9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2214 KTN9 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2214-TN9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 70×125×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2214 TN9 is the cylindrical-bore TN9 PA66-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2214-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K TN9 PA66-caged and cylindrical-bore full-complement V executions (186/196 kN vs 212/228 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22214",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope as the SKF spherical roller bearing SKF 22214 E, but catalogue C/C0 differ (186/196 kN vs 213/228 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22214-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope as the SKF spherical roller bearing SKF 22214 EK, but catalogue C/C0 differ (186/196 kN vs 213/228 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2214-KTN9",
      "C 2214 KTN9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2214-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2214 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 212,
    "static_load_kN": 228,
    "fatigue_load_limit_kN": 26.5,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 1550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2214 V belongs to the CARB family — compact aligning roller bearings: envelope 70×125×31 mm, radial rating 212/228 kN C/C0, and no axial-locating function by design. The designation C 2214 V separates into C (CARB), 22 (dimension series), 14 (70 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 70×125×31 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 70 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2214 V deliberately carries none. Mounting: slide the bearing onto the 70 mm seat or heat it (max 120 °C) and seat it square; never press through the 31 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 70 mm bore the small CARB executions are unusually wide (31 mm) for their 125 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2214 V must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 70 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 212/228 kN ratings and 1550 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (212 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2214 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 2214 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 70 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 31 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2214 V?",
        "a": "A C 2214 V measures 70 mm bore × 125 mm outside diameter × 31 mm width (2.756 × 4.921 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 212 kN, static C0 228 kN, fatigue limit Pu 26.5 kN, limiting speed 2,400 r/min, no reference speed listed, mass about 1550 g."
      },
      {
        "q": "Can a CARB bearing like C 2214 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 2214 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2214-TN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore TN9 PA66-caged executions (212/228 kN vs 186/196 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2214-KTN9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K TN9 PA66-caged executions (212/228 kN vs 186/196 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22214",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (70×125×31 mm) SKF spherical roller bearing SKF 22214 E with ratings within 10 % — not a drop-in substitute: SKF 22214 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22214-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (70×125×31 mm) SKF spherical roller bearing SKF 22214 EK with ratings within 10 % — not a drop-in substitute: SKF 22214 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2214-V",
      "C 2214 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2314",
    "brand": "SKF",
    "manufacturer_designation": "C 2314",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 405,
    "static_load_kN": 430,
    "fatigue_load_limit_kN": 49,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "weight_g": 4300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2314 denotes a toroidal roller bearing whose 51 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 2314 separates into C (CARB), 23 (dimension series), 14 (70 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 70×150×51 mm follows the ISO 15 plan. The cylindrical 70 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 70×150×51 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 51 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 51 mm wide cavity does not fill itself.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 70 mm bore the small CARB executions are unusually wide (51 mm) for their 150 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2314 must float; the two are designed to be used as a pair.",
      "Never use C 2314 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 70 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 405/430 kN ratings and 4300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2314 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 70 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 51 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2314?",
        "a": "A C 2314 measures 70 mm bore × 150 mm outside diameter × 51 mm width (2.756 × 5.906 × 2.008 in). From SKF catalogue PUB BU/P1 17000: dynamic C 405 kN, static C0 430 kN, fatigue limit Pu 49 kN, reference speed 3,800 r/min, limiting speed 5,000 r/min, mass about 4300 g."
      },
      {
        "q": "Can a CARB bearing like C 2314 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2314 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2314 designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 14 = 70 mm bore (code 14 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2314-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 70×150×51 mm ISO 15 envelope and equivalent catalogue C/C0; C 2314 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22314",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (70×150×51 mm) SKF spherical roller bearing SKF 22314 E with ratings within 10 % — not a drop-in substitute: SKF 22314 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22314-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (70×150×51 mm) SKF spherical roller bearing SKF 22314 EK with ratings within 10 % — not a drop-in substitute: SKF 22314 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2314",
      "C 2314"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2314-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2314 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 405,
    "static_load_kN": 430,
    "fatigue_load_limit_kN": 49,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "weight_g": 4300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2314 K combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 70 mm bore, 150 mm outside diameter, 51 mm wide unit rated 405 kN dynamic. The designation C 2314 K separates into C (CARB), 23 (dimension series), 14 (70 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 70×150×51 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 70 mm shaft deflects; the 3,800 r/min reference and 5,000 r/min limiting speed are both catalogue values. The 4300 g mass over the 70×150×51 mm envelope yields about 5.79 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 51 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 70 mm bore the small CARB executions are unusually wide (51 mm) for their 150 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 3,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 405/430 kN ratings belong to this exact execution (C 2314 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 70 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Never use C 2314 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 405/430 kN ratings and 4300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 858); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2314 K?",
        "a": "A C 2314 K measures 70 mm bore × 150 mm outside diameter × 51 mm width (2.756 × 5.906 × 2.008 in). From SKF catalogue PUB BU/P1 17000: dynamic C 405 kN, static C0 430 kN, fatigue limit Pu 49 kN, reference speed 3,800 r/min, limiting speed 5,000 r/min, mass about 4300 g."
      },
      {
        "q": "Can a CARB bearing like C 2314 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2314 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2314 K designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 14 = 70 mm bore (code 14 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (405 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2314 K is the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2314",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 70×150×51 mm ISO 15 envelope and equivalent catalogue C/C0; C 2314 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22314",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (70×150×51 mm) SKF spherical roller bearing SKF 22314 E with ratings within 10 % — not a drop-in substitute: SKF 22314 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22314-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (70×150×51 mm) SKF spherical roller bearing SKF 22314 EK with ratings within 10 % — not a drop-in substitute: SKF 22314 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2314-K",
      "C 2314 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C5915-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 5915-2CS5V/GEM9",
    "series": "C5900-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 166,
    "static_load_kN": 232,
    "fatigue_load_limit_kN": 30,
    "limiting_speed_rpm": 130,
    "max_rpm": 130,
    "weight_g": 3900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 5915-2CS5V/GEM9 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 75×105×40 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. SKF builds the CARB order number from size plus execution: the bare number C 5915 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here 2CS5V/GEM9. Both-side contact seals protect the full-complement roller set in contaminated housings, with grease for life at fitting. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 75 mm shaft deflects; no reference speed is listed and the limiting speed is 130 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 130 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: slide the bearing onto the 75 mm seat or heat it (max 120 °C) and seat it square; never press through the 40 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (40 mm) for their 105 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 5915-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 166/232 kN ratings belong to this exact execution (C 5915-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 166/232 kN ratings and 3900 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 5915-2CS5V/GEM9 have?",
        "a": "A C 5915-2CS5V/GEM9 measures 75 mm bore × 105 mm outside diameter × 40 mm width (2.953 × 4.134 × 1.575 in). From SKF catalogue PUB BU/P1 17000: dynamic C 166 kN, static C0 232 kN, fatigue limit Pu 30 kN, limiting speed 130 r/min, no reference speed listed, mass about 3900 g."
      },
      {
        "q": "What does C 5915-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 59 the dimension series; the size code gives 75 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 5915-2CS5V/GEM9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C5915-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×105×40 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (166/232 kN vs 204/325 kN) — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C5915-2CS5V-GEM9",
      "C 5915-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C5915-V",
    "brand": "SKF",
    "manufacturer_designation": "C 5915 V",
    "series": "C5900-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 204,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 38,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "weight_g": 1100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 5915 V is the dimension series 59 CARB toroidal roller bearings member of the CARB range: 75 mm bore, 105 mm OD, 40 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 5915 V separates into C (CARB), 59 (dimension series), 15 (75 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 75×105×40 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 75 mm seat. Selection arithmetic: C 204 kN against C0 325 kN gives a C0/C ratio of 1.59, and the 38 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 105 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (40 mm) for their 105 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Never use C 5915 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The quoted 204/325 kN ratings belong to this exact execution (C 5915 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 204/325 kN ratings and 1100 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 5915 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 5915 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 5915 V designation read?",
        "a": "C = CARB toroidal family; 59 = dimension series; 15 = 75 mm bore (code 15 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (204 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 5915 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 5915 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 75 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 40 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C5915-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×105×40 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (204/325 kN vs 166/232 kN) — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C5915-V",
      "C 5915 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6915-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 6915-2CS5V/GEM9",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 204,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 37.5,
    "limiting_speed_rpm": 140,
    "max_rpm": 140,
    "weight_g": 1400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 6915-2CS5V/GEM9 denotes a toroidal roller bearing whose 54 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. In C 6915-2CS5V/GEM9 the 69 dimension series fixes the 105 mm OD and 54 mm width around the 75 mm bore (the bore is written directly after the slash (no bore code)); the suffix 2CS5V/GEM9 then selects the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 75 mm seat. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 54 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 105 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (54 mm) for their 105 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 6915-2CS5V/GEM9 must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 204/325 kN ratings and 1400 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 6915-2CS5V/GEM9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 75 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 54 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 6915-2CS5V/GEM9?",
        "a": "A C 6915-2CS5V/GEM9 measures 75 mm bore × 105 mm outside diameter × 54 mm width (2.953 × 4.134 × 2.126 in). From SKF catalogue PUB BU/P1 17000: dynamic C 204 kN, static C0 325 kN, fatigue limit Pu 37.5 kN, limiting speed 140 r/min, no reference speed listed, mass about 1400 g."
      },
      {
        "q": "Can a CARB bearing like C 6915-2CS5V/GEM9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 6915-2CS5V/GEM9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 6915-2CS5V/GEM9 designation read?",
        "a": "C = CARB toroidal family; 69 = dimension series; 75 mm (slash-size) = 75 mm bore (the bore is written directly after the slash (no bore code)); suffix 2CS5V/GEM9 selects cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6915-V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×105×54 mm ISO 15 envelope and equivalent catalogue C/C0; C 6915 V/VE240 is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6915-2CS5V-GEM9",
      "C 6915-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C6915-V-VE240",
    "brand": "SKF",
    "manufacturer_designation": "C 6915 V/VE240",
    "series": "C6900-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 204,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 37.5,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "weight_g": 1400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 6915 V/VE240 denotes a toroidal roller bearing whose 54 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 6915 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V/VE240. The V suffix denotes a full complement: the toroidal rollers fill the 54 mm space without a cage, raising C to 204 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 54 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (54 mm) for their 105 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 6915 V/VE240 must float; the two are designed to be used as a pair.",
      "Never use C 6915 V/VE240 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 204/325 kN ratings and 1400 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 6915 V/VE240 have?",
        "a": "A C 6915 V/VE240 measures 75 mm bore × 105 mm outside diameter × 54 mm width (2.953 × 4.134 × 2.126 in). From SKF catalogue PUB BU/P1 17000: dynamic C 204 kN, static C0 325 kN, fatigue limit Pu 37.5 kN, limiting speed 1,900 r/min, no reference speed listed, mass about 1400 g."
      },
      {
        "q": "What does C 6915 V/VE240 mean in SKF part numbering?",
        "a": "C marks CARB; 69 the dimension series; the size code gives 75 mm bore; V/VE240 is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 6915 V/VE240 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C6915-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×105×54 mm ISO 15 envelope and equivalent catalogue C/C0; C 6915-2CS5V/GEM9 is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C6915-V-VE240",
      "C 6915 V/VE240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4015-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4015 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 115,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 208,
    "static_load_kN": 345,
    "fatigue_load_limit_kN": 40.5,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "weight_g": 1600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4015 V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 75×115×40 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (15) encode the 75 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 75 mm shaft deflects; no reference speed is listed and the limiting speed is 2,000 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 2,000 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 40 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (40 mm) for their 115 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4015 V must float; the two are designed to be used as a pair.",
      "Never use C 4015 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 208/345 kN ratings and 1600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 4015 V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 75 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4015 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4015 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24015",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×115×40 mm envelope as the SKF spherical roller bearing SKF 24015 CC/W33, but catalogue C/C0 differ (208/345 kN vs 181/232 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4015-V",
      "C 4015 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2215",
    "brand": "SKF",
    "manufacturer_designation": "C 2215",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 196,
    "static_load_kN": 208,
    "fatigue_load_limit_kN": 24,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "weight_g": 1600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2215 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 75×130×31 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 2215 separates into C (CARB), 22 (dimension series), 15 (75 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 75×130×31 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 75 mm seat. The 1600 g mass over the 75×130×31 mm envelope yields about 2.61 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: slide the bearing onto the 75 mm seat or heat it (max 120 °C) and seat it square; never press through the 31 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (31 mm) for their 130 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2215 must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 196/208 kN ratings and 1600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (196 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2215 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 2215 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 75 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 31 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2215?",
        "a": "A C 2215 measures 75 mm bore × 130 mm outside diameter × 31 mm width (2.953 × 5.118 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 196 kN, static C0 208 kN, fatigue limit Pu 24 kN, reference speed 4,800 r/min, limiting speed 6,700 r/min, mass about 1600 g."
      },
      {
        "q": "Can a CARB bearing like C 2215 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2215 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2215-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×130×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2215 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2215-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and cylindrical-bore full-complement V executions (196/208 kN vs 220/240 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2215-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and 1:12 tapered-bore K full-complement V executions (196/208 kN vs 220/240 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22215",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope as the SKF spherical roller bearing SKF 22215 E, but catalogue C/C0 differ (196/208 kN vs 217/240 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22215-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope as the SKF spherical roller bearing SKF 22215 EK, but catalogue C/C0 differ (196/208 kN vs 217/240 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2215",
      "C 2215"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2215-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2215 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 196,
    "static_load_kN": 208,
    "fatigue_load_limit_kN": 24,
    "reference_speed_rpm": 4800,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "weight_g": 1600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2215 K belongs to the CARB family — compact aligning roller bearings: envelope 75×130×31 mm, radial rating 196/208 kN C/C0, and no axial-locating function by design. In C 2215 K the 22 dimension series fixes the 130 mm OD and 31 mm width around the 75 mm bore (code 15 × 5); the suffix K then selects the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. The K suffix gives a 1:12 tapered 75 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 75×130×31 mm are identical — only the mounting method changes. Selection arithmetic: C 196 kN against C0 208 kN gives a C0/C ratio of 1.06, and the 24 kN fatigue load limit Pu sets the contamination-adjusted life floor. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (31 mm) for their 130 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 4,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 196/208 kN ratings belong to this exact execution (C 2215 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2215 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 196/208 kN ratings and 1600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2215 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2215 K?",
        "a": "A C 2215 K measures 75 mm bore × 130 mm outside diameter × 31 mm width (2.953 × 5.118 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 196 kN, static C0 208 kN, fatigue limit Pu 24 kN, reference speed 4,800 r/min, limiting speed 6,700 r/min, mass about 1600 g."
      },
      {
        "q": "Can a CARB bearing like C 2215 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2215 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2215 K designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 15 = 75 mm bore (code 15 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2215",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×130×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2215 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2215-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K steel-caged and cylindrical-bore full-complement V executions (196/208 kN vs 220/240 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2215-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K steel-caged and 1:12 tapered-bore K full-complement V executions (196/208 kN vs 220/240 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22215",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope as the SKF spherical roller bearing SKF 22215 E, but catalogue C/C0 differ (196/208 kN vs 217/240 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22215-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope as the SKF spherical roller bearing SKF 22215 EK, but catalogue C/C0 differ (196/208 kN vs 217/240 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2215-K",
      "C 2215 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2215-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2215 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 220,
    "static_load_kN": 240,
    "fatigue_load_limit_kN": 28,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "weight_g": 1650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2215 V in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (15) encode the 75 mm bore; suffixes describe bore and execution. The cylindrical 75 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 75×130×31 mm are identical — only the mounting method changes. Selection arithmetic: C 220 kN against C0 240 kN gives a C0/C ratio of 1.09, and the 28 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: slide the bearing onto the 75 mm seat or heat it (max 120 °C) and seat it square; never press through the 31 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (31 mm) for their 130 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 220/240 kN ratings belong to this exact execution (C 2215 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 220/240 kN ratings and 1650 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2215 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2215 V have?",
        "a": "A C 2215 V measures 75 mm bore × 130 mm outside diameter × 31 mm width (2.953 × 5.118 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 220 kN, static C0 240 kN, fatigue limit Pu 28 kN, limiting speed 2,200 r/min, no reference speed listed, mass about 1650 g."
      },
      {
        "q": "What does C 2215 V mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 75 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2215",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore steel-caged executions (220/240 kN vs 196/208 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2215-K",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K steel-caged executions (220/240 kN vs 196/208 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2215-KV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×130×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2215 KV is the 1:12 tapered-bore K full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22215",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×130×31 mm) SKF spherical roller bearing SKF 22215 E with ratings within 10 % — not a drop-in substitute: SKF 22215 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22215-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×130×31 mm) SKF spherical roller bearing SKF 22215 EK with ratings within 10 % — not a drop-in substitute: SKF 22215 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2215-V",
      "C 2215 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2215-KV",
    "brand": "SKF",
    "manufacturer_designation": "C 2215 KV",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 220,
    "static_load_kN": 240,
    "fatigue_load_limit_kN": 28,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "weight_g": 1650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2215 KV denotes a toroidal roller bearing whose 31 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (15) encode the 75 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 75 mm shaft deflects; no reference speed is listed and the limiting speed is 2,200 r/min. The 1650 g mass over the 75×130×31 mm envelope yields about 2.93 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 31 mm wide cavity does not fill itself.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (31 mm) for their 130 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 2215 KV as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 220/240 kN ratings belong to this exact execution (C 2215 KV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 220/240 kN ratings and 1650 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2215 KV have?",
        "a": "A C 2215 KV measures 75 mm bore × 130 mm outside diameter × 31 mm width (2.953 × 5.118 × 1.22 in). From SKF catalogue PUB BU/P1 17000: dynamic C 220 kN, static C0 240 kN, fatigue limit Pu 28 kN, limiting speed 2,200 r/min, no reference speed listed, mass about 1650 g."
      },
      {
        "q": "What does C 2215 KV mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 75 mm bore; KV is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2215 KV used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2215 KV sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2215",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and cylindrical-bore steel-caged executions (220/240 kN vs 196/208 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2215-K",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×31 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and 1:12 tapered-bore K steel-caged executions (220/240 kN vs 196/208 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2215-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×130×31 mm ISO 15 envelope and equivalent catalogue C/C0; C 2215 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22215",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×130×31 mm) SKF spherical roller bearing SKF 22215 E with ratings within 10 % — not a drop-in substitute: SKF 22215 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22215-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×130×31 mm) SKF spherical roller bearing SKF 22215 EK with ratings within 10 % — not a drop-in substitute: SKF 22215 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2215-KV",
      "C 2215 KV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2315",
    "brand": "SKF",
    "manufacturer_designation": "C 2315",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 425,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 52,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 5300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2315 belongs to the CARB family — compact aligning roller bearings: envelope 75×160×55 mm, radial rating 425/465 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (23) identify the ISO dimension series and the last two (15) encode the 75 mm bore; suffixes describe bore and execution. The cylindrical 75 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 75×160×55 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 55 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 75 mm seat or heat it (max 120 °C) and seat it square; never press through the 55 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (55 mm) for their 160 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 425/465 kN ratings belong to this exact execution (C 2315); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 425/465 kN ratings and 5300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2315 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2315 have?",
        "a": "A C 2315 measures 75 mm bore × 160 mm outside diameter × 55 mm width (2.953 × 6.299 × 2.165 in). From SKF catalogue PUB BU/P1 17000: dynamic C 425 kN, static C0 465 kN, fatigue limit Pu 52 kN, reference speed 3,600 r/min, limiting speed 4,800 r/min, mass about 5300 g."
      },
      {
        "q": "What does C 2315 mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 75 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2315-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×160×55 mm ISO 15 envelope and equivalent catalogue C/C0; C 2315 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22315",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×160×55 mm) SKF spherical roller bearing SKF 22315 E with ratings within 10 % — not a drop-in substitute: SKF 22315 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22315-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×160×55 mm) SKF spherical roller bearing SKF 22315 EK with ratings within 10 % — not a drop-in substitute: SKF 22315 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2315",
      "C 2315"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2315-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2315 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 425,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 52,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 5300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2315 K is the dimension series 23 CARB toroidal roller bearings member of the CARB range: 75 mm bore, 160 mm OD, 55 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. In C 2315 K the 23 dimension series fixes the 160 mm OD and 55 mm width around the 75 mm bore (code 15 × 5); the suffix K then selects the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 75 mm seat. The 5300 g mass over the 75×160×55 mm envelope yields about 5.67 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 55 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 75 mm bore the small CARB executions are unusually wide (55 mm) for their 160 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Never use C 2315 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 75 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 425/465 kN ratings belong to this exact execution (C 2315 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 425/465 kN ratings and 5300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2315 K?",
        "a": "A C 2315 K measures 75 mm bore × 160 mm outside diameter × 55 mm width (2.953 × 6.299 × 2.165 in). From SKF catalogue PUB BU/P1 17000: dynamic C 425 kN, static C0 465 kN, fatigue limit Pu 52 kN, reference speed 3,600 r/min, limiting speed 4,800 r/min, mass about 5300 g."
      },
      {
        "q": "Can a CARB bearing like C 2315 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2315 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2315 K designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 15 = 75 mm bore (code 15 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (425 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2315 K is the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2315",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 75×160×55 mm ISO 15 envelope and equivalent catalogue C/C0; C 2315 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22315",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×160×55 mm) SKF spherical roller bearing SKF 22315 E with ratings within 10 % — not a drop-in substitute: SKF 22315 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22315-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (75×160×55 mm) SKF spherical roller bearing SKF 22315 EK with ratings within 10 % — not a drop-in substitute: SKF 22315 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2315-K",
      "C 2315 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2216",
    "brand": "SKF",
    "manufacturer_designation": "C 2216",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 220,
    "static_load_kN": 250,
    "fatigue_load_limit_kN": 28.5,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 2050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2216 in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (16) encode the 80 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 80 mm seat. The 2050 g mass over the 80×140×33 mm envelope yields about 2.75 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 80 mm bore the small CARB executions are unusually wide (33 mm) for their 140 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "The quoted 220/250 kN ratings belong to this exact execution (C 2216); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Reference and limiting speeds are different limits: the 4,300 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 2216 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 220/250 kN ratings and 2050 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 2216 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2216 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2216 have?",
        "a": "A C 2216 measures 80 mm bore × 140 mm outside diameter × 33 mm width (3.15 × 5.512 × 1.299 in). From SKF catalogue PUB BU/P1 17000: dynamic C 220 kN, static C0 250 kN, fatigue limit Pu 28.5 kN, reference speed 4,300 r/min, limiting speed 6,000 r/min, mass about 2050 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2216-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 80×140×33 mm ISO 15 envelope and equivalent catalogue C/C0; C 2216 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2216-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and cylindrical-bore full-complement V executions (220/250 kN vs 255/305 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2216-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and 1:12 tapered-bore K full-complement V executions (220/250 kN vs 255/305 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 E, but catalogue C/C0 differ (220/250 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22216-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 EK, but catalogue C/C0 differ (220/250 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2216",
      "C 2216"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2216-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2216 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 220,
    "static_load_kN": 250,
    "fatigue_load_limit_kN": 28.5,
    "reference_speed_rpm": 4300,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 2050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2216 K in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. SKF builds the CARB order number from size plus execution: the bare number C 2216 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 80×140 mm size with 220 kN dynamic and a 4,300 r/min reference speed. Speed planning separates the 4,300 r/min thermal reference from the 6,000 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 80 mm bore the small CARB executions are unusually wide (33 mm) for their 140 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 80 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 4,300 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 220/250 kN ratings belong to this exact execution (C 2216 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2216 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 220/250 kN ratings and 2050 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2216 K have?",
        "a": "A C 2216 K measures 80 mm bore × 140 mm outside diameter × 33 mm width (3.15 × 5.512 × 1.299 in). From SKF catalogue PUB BU/P1 17000: dynamic C 220 kN, static C0 250 kN, fatigue limit Pu 28.5 kN, reference speed 4,300 r/min, limiting speed 6,000 r/min, mass about 2050 g."
      },
      {
        "q": "What does C 2216 K mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 80 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2216 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2216",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 80×140×33 mm ISO 15 envelope and equivalent catalogue C/C0; C 2216 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C2216-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K steel-caged and cylindrical-bore full-complement V executions (220/250 kN vs 255/305 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2216-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K steel-caged and 1:12 tapered-bore K full-complement V executions (220/250 kN vs 255/305 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "22216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 E, but catalogue C/C0 differ (220/250 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22216-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 EK, but catalogue C/C0 differ (220/250 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2216-K",
      "C 2216 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2216-V",
    "brand": "SKF",
    "manufacturer_designation": "C 2216 V",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 255,
    "static_load_kN": 305,
    "fatigue_load_limit_kN": 34.5,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "weight_g": 2150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2216 V: the toroidal rollers allow the 80 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. In C 2216 V the 22 dimension series fixes the 140 mm OD and 33 mm width around the 80 mm bore (code 16 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The V suffix denotes a full complement: the toroidal rollers fill the 33 mm space without a cage, raising C to 255 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 2,000 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: slide the bearing onto the 80 mm seat or heat it (max 120 °C) and seat it square; never press through the 33 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 80 mm bore the small CARB executions are unusually wide (33 mm) for their 140 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 255/305 kN ratings belong to this exact execution (C 2216 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 80 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Never use C 2216 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 255/305 kN ratings and 2150 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (255 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2216 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 2216 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 80 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 33 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2216 V?",
        "a": "A C 2216 V measures 80 mm bore × 140 mm outside diameter × 33 mm width (3.15 × 5.512 × 1.299 in). From SKF catalogue PUB BU/P1 17000: dynamic C 255 kN, static C0 305 kN, fatigue limit Pu 34.5 kN, limiting speed 2,000 r/min, no reference speed listed, mass about 2150 g."
      },
      {
        "q": "Can a CARB bearing like C 2216 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 2216 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore steel-caged executions (255/305 kN vs 220/250 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2216-K",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:12 tapered-bore K steel-caged executions (255/305 kN vs 220/250 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2216-KV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 80×140×33 mm ISO 15 envelope and equivalent catalogue C/C0; C 2216 KV is the 1:12 tapered-bore K full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 E, but catalogue C/C0 differ (255/305 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22216-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 EK, but catalogue C/C0 differ (255/305 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2216-V",
      "C 2216 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2216-KV",
    "brand": "SKF",
    "manufacturer_designation": "C 2216 KV",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 255,
    "static_load_kN": 305,
    "fatigue_load_limit_kN": 34.5,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "weight_g": 2150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2216 KV in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. In C 2216 KV the 22 dimension series fixes the 140 mm OD and 33 mm width around the 80 mm bore (code 16 × 5); the suffix KV then selects the tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage). The V suffix denotes a full complement: the toroidal rollers fill the 33 mm space without a cage, raising C to 255 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Selection arithmetic: C 255 kN against C0 305 kN gives a C0/C ratio of 1.20, and the 34.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 140 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 80 mm bore the small CARB executions are unusually wide (33 mm) for their 140 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 255/305 kN ratings belong to this exact execution (C 2216 KV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2216 KV as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 255/305 kN ratings and 2150 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2216 KV mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2216 KV?",
        "a": "A C 2216 KV measures 80 mm bore × 140 mm outside diameter × 33 mm width (3.15 × 5.512 × 1.299 in). From SKF catalogue PUB BU/P1 17000: dynamic C 255 kN, static C0 305 kN, fatigue limit Pu 34.5 kN, limiting speed 2,000 r/min, no reference speed listed, mass about 2150 g."
      },
      {
        "q": "Can a CARB bearing like C 2216 KV locate the shaft axially?",
        "a": "No — that is the defining feature. C 2216 KV deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2216 KV designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 16 = 80 mm bore (code 16 × 5); suffix KV selects tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and cylindrical-bore steel-caged executions (255/305 kN vs 220/250 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2216-K",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and 1:12 tapered-bore K steel-caged executions (255/305 kN vs 220/250 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C2216-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 80×140×33 mm ISO 15 envelope and equivalent catalogue C/C0; C 2216 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 E, but catalogue C/C0 differ (255/305 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22216-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×33 mm envelope as the SKF spherical roller bearing SKF 22216 EK, but catalogue C/C0 differ (255/305 kN vs 243/270 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2216-KV",
      "C 2216 KV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2316",
    "brand": "SKF",
    "manufacturer_designation": "C 2316",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 510,
    "static_load_kN": 550,
    "fatigue_load_limit_kN": 60,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 6300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2316: the toroidal rollers allow the 80 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. In C 2316 the 23 dimension series fixes the 170 mm OD and 58 mm width around the 80 mm bore (code 16 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. The cylindrical 80 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 80×170×58 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 58 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 80 mm bore the small CARB executions are unusually wide (58 mm) for their 170 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Reference and limiting speeds are different limits: the 3,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 510/550 kN ratings belong to this exact execution (C 2316); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2316 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 80 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 510/550 kN ratings and 6300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 2316 designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 16 = 80 mm bore (code 16 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (510 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2316 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 2316 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 80 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 58 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2316?",
        "a": "A C 2316 measures 80 mm bore × 170 mm outside diameter × 58 mm width (3.15 × 6.693 × 2.283 in). From SKF catalogue PUB BU/P1 17000: dynamic C 510 kN, static C0 550 kN, fatigue limit Pu 60 kN, reference speed 3,400 r/min, limiting speed 4,500 r/min, mass about 6300 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2316-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 80×170×58 mm ISO 15 envelope and equivalent catalogue C/C0; C 2316 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22316",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (80×170×58 mm) SKF spherical roller bearing SKF 22316 E with ratings within 10 % — not a drop-in substitute: SKF 22316 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22316-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (80×170×58 mm) SKF spherical roller bearing SKF 22316 EK with ratings within 10 % — not a drop-in substitute: SKF 22316 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2316",
      "C 2316"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2316-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2316 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 510,
    "static_load_kN": 550,
    "fatigue_load_limit_kN": 60,
    "reference_speed_rpm": 3400,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 6300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2316 K denotes a toroidal roller bearing whose 58 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 2316 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K. The K suffix gives a 1:12 tapered 80 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 80×170×58 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 58 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 58 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 80 mm bore the small CARB executions are unusually wide (58 mm) for their 170 mm OD — confirm the housing width before substituting a standard spherical bearing of the same bore.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2316 K must float; the two are designed to be used as a pair.",
      "Never use C 2316 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 80 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 510/550 kN ratings and 6300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2316 K have?",
        "a": "A C 2316 K measures 80 mm bore × 170 mm outside diameter × 58 mm width (3.15 × 6.693 × 2.283 in). From SKF catalogue PUB BU/P1 17000: dynamic C 510 kN, static C0 550 kN, fatigue limit Pu 60 kN, reference speed 3,400 r/min, limiting speed 4,500 r/min, mass about 6300 g."
      },
      {
        "q": "What does C 2316 K mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 80 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2316 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2316 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2316",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 80×170×58 mm ISO 15 envelope and equivalent catalogue C/C0; C 2316 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22316",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (80×170×58 mm) SKF spherical roller bearing SKF 22316 E with ratings within 10 % — not a drop-in substitute: SKF 22316 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22316-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (80×170×58 mm) SKF spherical roller bearing SKF 22316 EK with ratings within 10 % — not a drop-in substitute: SKF 22316 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2316-K",
      "C 2316 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2217",
    "brand": "SKF",
    "manufacturer_designation": "C 2217",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 275,
    "static_load_kN": 320,
    "fatigue_load_limit_kN": 35.5,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "weight_g": 2650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2217 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 85 mm bore, 150 mm outside diameter, 36 mm wide unit rated 275 kN dynamic. In C 2217 the 22 dimension series fixes the 150 mm OD and 36 mm width around the 85 mm bore (code 17 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 85 mm seat. The 2650 g mass over the 85×150×36 mm envelope yields about 3.24 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 150 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 85 mm bore, shaft expansion is already measurable: calculate the required float inside the 36 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 4,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 275/320 kN ratings belong to this exact execution (C 2217); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2217 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 275/320 kN ratings and 2650 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 2217 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2217 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2217 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 17 = 85 mm bore (code 17 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (275 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2217 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 2217 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 85 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 36 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2217-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 85×150×36 mm ISO 15 envelope and equivalent catalogue C/C0; C 2217 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22217",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×150×36 mm) SKF spherical roller bearing SKF 22217 E with ratings within 10 % — not a drop-in substitute: SKF 22217 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22217-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×150×36 mm) SKF spherical roller bearing SKF 22217 EK with ratings within 10 % — not a drop-in substitute: SKF 22217 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2217",
      "C 2217"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2217-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2217 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 275,
    "static_load_kN": 320,
    "fatigue_load_limit_kN": 35.5,
    "reference_speed_rpm": 4000,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "weight_g": 2650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2217 K: the toroidal rollers allow the 85 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (17) encode the 85 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 85 mm shaft deflects; the 4,000 r/min reference and 5,600 r/min limiting speed are both catalogue values. Speed planning separates the 4,000 r/min thermal reference from the 5,600 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 85 mm bore, shaft expansion is already measurable: calculate the required float inside the 36 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2217 K must float; the two are designed to be used as a pair.",
      "Never use C 2217 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Reference and limiting speeds are different limits: the 4,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 275/320 kN ratings belong to this exact execution (C 2217 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 275/320 kN ratings and 2650 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2217 K have?",
        "a": "A C 2217 K measures 85 mm bore × 150 mm outside diameter × 36 mm width (3.346 × 5.906 × 1.417 in). From SKF catalogue PUB BU/P1 17000: dynamic C 275 kN, static C0 320 kN, fatigue limit Pu 35.5 kN, reference speed 4,000 r/min, limiting speed 5,600 r/min, mass about 2650 g."
      },
      {
        "q": "What does C 2217 K mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 85 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2217 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2217",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 85×150×36 mm ISO 15 envelope and equivalent catalogue C/C0; C 2217 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22217",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×150×36 mm) SKF spherical roller bearing SKF 22217 E with ratings within 10 % — not a drop-in substitute: SKF 22217 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22217-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×150×36 mm) SKF spherical roller bearing SKF 22217 EK with ratings within 10 % — not a drop-in substitute: SKF 22217 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2217-K",
      "C 2217 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2317",
    "brand": "SKF",
    "manufacturer_designation": "C 2317",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 540,
    "static_load_kN": 600,
    "fatigue_load_limit_kN": 64,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 7400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2317 is the dimension series 23 CARB toroidal roller bearings member of the CARB range: 85 mm bore, 180 mm OD, 60 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. SKF builds the CARB order number from size plus execution: the bare number C 2317 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here the bare number. The cylindrical 85 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 85×180×60 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 60 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 180 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 85 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 85 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,200 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 540/600 kN ratings belong to this exact execution (C 2317); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 540/600 kN ratings and 7400 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 2317 mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 85 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2317 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2317 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2317-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 85×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 2317 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22317",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×180×60 mm) SKF spherical roller bearing SKF 22317 E with ratings within 10 % — not a drop-in substitute: SKF 22317 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22317-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×180×60 mm) SKF spherical roller bearing SKF 22317 EK with ratings within 10 % — not a drop-in substitute: SKF 22317 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2317",
      "C 2317"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2317-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2317 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 540,
    "static_load_kN": 600,
    "fatigue_load_limit_kN": 64,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 7400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2317 K is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 85×180×60 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 2317 K separates into C (CARB), 23 (dimension series), 17 (85 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 85×180×60 mm follows the ISO 15 plan. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 85×180 mm size with 540 kN dynamic and a 3,200 r/min reference speed. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2317 K deliberately carries none. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 60 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 85 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2317 K must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 85 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,200 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 540/600 kN ratings and 7400 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2317 K?",
        "a": "A C 2317 K measures 85 mm bore × 180 mm outside diameter × 60 mm width (3.346 × 7.087 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 540 kN, static C0 600 kN, fatigue limit Pu 64 kN, reference speed 3,200 r/min, limiting speed 4,300 r/min, mass about 7400 g."
      },
      {
        "q": "Can a CARB bearing like C 2317 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2317 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2317 K designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 17 = 85 mm bore (code 17 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (540 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2317 K is the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2317",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 85×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 2317 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22317",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×180×60 mm) SKF spherical roller bearing SKF 22317 E with ratings within 10 % — not a drop-in substitute: SKF 22317 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22317-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (85×180×60 mm) SKF spherical roller bearing SKF 22317 EK with ratings within 10 % — not a drop-in substitute: SKF 22317 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2317-K",
      "C 2317 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C5918-MB",
    "brand": "SKF",
    "manufacturer_designation": "C 5918 MB",
    "series": "C5900-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 125,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 193,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 37.5,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "weight_g": 1750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 5918 MB combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 90 mm bore, 125 mm outside diameter, 46 mm wide unit rated 193 kN dynamic. The designation C 5918 MB separates into C (CARB), 59 (dimension series), 18 (90 mm bore) and MB (cylindrical bore for direct shaft fitting, machined inner-ring-guided brass cage (MB)); envelope 90×125×46 mm follows the ISO 15 plan. The MB suffix is a machined two-piece brass cage guided on the inner ring, the standard choice for wide, large-bore CARB sizes where a polymer cage would run beyond its temperature or load limit. The 1750 g mass over the 90×125×46 mm envelope yields about 2.14 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 125 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 5918 MB as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 193/325 kN ratings belong to this exact execution (C 5918 MB); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 193/325 kN ratings and 1750 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 5918 MB mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 90 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 46 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 5918 MB?",
        "a": "A C 5918 MB measures 90 mm bore × 125 mm outside diameter × 46 mm width (3.543 × 4.921 × 1.811 in). From SKF catalogue PUB BU/P1 17000: dynamic C 193 kN, static C0 325 kN, fatigue limit Pu 37.5 kN, reference speed 2,600 r/min, limiting speed 4,000 r/min, mass about 1750 g."
      },
      {
        "q": "Can a CARB bearing like C 5918 MB locate the shaft axially?",
        "a": "No — that is the defining feature. C 5918 MB deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 5918 MB designation read?",
        "a": "C = CARB toroidal family; 59 = dimension series; 18 = 90 mm bore (code 18 × 5); suffix MB selects cylindrical bore for direct shaft fitting, machined inner-ring-guided brass cage (MB). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C5918-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×125×46 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore sealed full-complement V executions (193/325 kN vs 224/400 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C5918-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×125×46 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore full-complement V executions (193/325 kN vs 224/400 kN) — envelope match, not a load-rating equivalent."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C5918-MB",
      "C 5918 MB"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C5918-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 5918-2CS5V/GEM9",
    "series": "C5900-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 125,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 224,
    "static_load_kN": 400,
    "fatigue_load_limit_kN": 44,
    "limiting_speed_rpm": 110,
    "max_rpm": 110,
    "weight_g": 1750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 5918-2CS5V/GEM9 belongs to the CARB family — compact aligning roller bearings: envelope 90×125×46 mm, radial rating 224/400 kN C/C0, and no axial-locating function by design. SKF builds the CARB order number from size plus execution: the bare number C 5918 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here 2CS5V/GEM9. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 90 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 5918-2CS5V/GEM9 deliberately carries none. Sealed executions arrive greased for life: do not wash out the factory fill, and mount seals-clear of the housing shoulder edges. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 46 mm wide cavity does not fill itself.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 5918-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 224/400 kN ratings belong to this exact execution (C 5918-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 224/400 kN ratings and 1750 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 5918-2CS5V/GEM9 sealed?",
        "a": "Yes — this is a sealed full-complement execution (2CS5V contact seals with annular groove), greased at the factory; the catalogue lists no reference speed and the limiting speed is 110 r/min."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 5918-2CS5V/GEM9 have?",
        "a": "A C 5918-2CS5V/GEM9 measures 90 mm bore × 125 mm outside diameter × 46 mm width (3.543 × 4.921 × 1.811 in). From SKF catalogue PUB BU/P1 17000: dynamic C 224 kN, static C0 400 kN, fatigue limit Pu 44 kN, limiting speed 110 r/min, no reference speed listed, mass about 1750 g."
      },
      {
        "q": "What does C 5918-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 59 the dimension series; the size code gives 90 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C5918-MB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×125×46 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore MB inner-ring-guided brass-caged executions (224/400 kN vs 193/325 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C5918-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 90×125×46 mm ISO 15 envelope and equivalent catalogue C/C0; C 5918 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C5918-2CS5V-GEM9",
      "C 5918-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C5918-V",
    "brand": "SKF",
    "manufacturer_designation": "C 5918 V",
    "series": "C5900-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 125,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 224,
    "static_load_kN": 400,
    "fatigue_load_limit_kN": 45.5,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "weight_g": 1750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 5918 V belongs to the CARB family — compact aligning roller bearings: envelope 90×125×46 mm, radial rating 224/400 kN C/C0, and no axial-locating function by design. SKF builds the CARB order number from size plus execution: the bare number C 5918 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 90 mm shaft deflects; no reference speed is listed and the limiting speed is 1,600 r/min. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 46 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 125 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 224/400 kN ratings belong to this exact execution (C 5918 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 5918 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 224/400 kN ratings and 1750 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 5918 V mean in SKF part numbering?",
        "a": "C marks CARB; 59 the dimension series; the size code gives 90 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 5918 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 5918 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C5918-MB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×125×46 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore MB inner-ring-guided brass-caged executions (224/400 kN vs 193/325 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C5918-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 90×125×46 mm ISO 15 envelope and equivalent catalogue C/C0; C 5918-2CS5V/GEM9 is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C5918-V",
      "C 5918 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2218",
    "brand": "SKF",
    "manufacturer_designation": "C 2218",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 325,
    "static_load_kN": 380,
    "fatigue_load_limit_kN": 41.5,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 3300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2218 denotes a toroidal roller bearing whose 40 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 2218 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here the bare number. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 90 mm seat. The 3300 g mass over the 90×160×40 mm envelope yields about 3.61 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 40 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 40 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2218 must float; the two are designed to be used as a pair.",
      "The 325/380 kN ratings and 3300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2218 have?",
        "a": "A C 2218 measures 90 mm bore × 160 mm outside diameter × 40 mm width (3.543 × 6.299 × 1.575 in). From SKF catalogue PUB BU/P1 17000: dynamic C 325 kN, static C0 380 kN, fatigue limit Pu 41.5 kN, reference speed 3,800 r/min, limiting speed 5,300 r/min, mass about 3300 g."
      },
      {
        "q": "What does C 2218 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 90 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2218 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2218 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2218-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 90×160×40 mm ISO 15 envelope and equivalent catalogue C/C0; C 2218 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22218",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×160×40 mm) SKF spherical roller bearing SKF 22218 E with ratings within 10 % — not a drop-in substitute: SKF 22218 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22218-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×160×40 mm) SKF spherical roller bearing SKF 22218 EK with ratings within 10 % — not a drop-in substitute: SKF 22218 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2218",
      "C 2218"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2218-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2218 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 325,
    "static_load_kN": 380,
    "fatigue_load_limit_kN": 41.5,
    "reference_speed_rpm": 3800,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 3300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2218 K combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 90 mm bore, 160 mm outside diameter, 40 mm wide unit rated 325 kN dynamic. In C 2218 K the 22 dimension series fixes the 160 mm OD and 40 mm width around the 90 mm bore (code 18 × 5); the suffix K then selects the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 90 mm seat. The 3300 g mass over the 90×160×40 mm envelope yields about 3.61 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 40 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2218 K must float; the two are designed to be used as a pair.",
      "Reference and limiting speeds are different limits: the 3,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 325/380 kN ratings belong to this exact execution (C 2218 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 325/380 kN ratings and 3300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2218 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2218 K?",
        "a": "A C 2218 K measures 90 mm bore × 160 mm outside diameter × 40 mm width (3.543 × 6.299 × 1.575 in). From SKF catalogue PUB BU/P1 17000: dynamic C 325 kN, static C0 380 kN, fatigue limit Pu 41.5 kN, reference speed 3,800 r/min, limiting speed 5,300 r/min, mass about 3300 g."
      },
      {
        "q": "Can a CARB bearing like C 2218 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2218 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2218 K designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 18 = 90 mm bore (code 18 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2218",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 90×160×40 mm ISO 15 envelope and equivalent catalogue C/C0; C 2218 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22218",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×160×40 mm) SKF spherical roller bearing SKF 22218 E with ratings within 10 % — not a drop-in substitute: SKF 22218 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22218-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×160×40 mm) SKF spherical roller bearing SKF 22218 EK with ratings within 10 % — not a drop-in substitute: SKF 22218 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2218-K",
      "C 2218 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2318",
    "brand": "SKF",
    "manufacturer_designation": "C 2318",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 610,
    "static_load_kN": 695,
    "fatigue_load_limit_kN": 73.5,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "weight_g": 8650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2318 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 90×190×64 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 2318 separates into C (CARB), 23 (dimension series), 18 (90 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 90×190×64 mm follows the ISO 15 plan. The cylindrical 90 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 90×190×64 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 64 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 64 mm wide cavity does not fill itself.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 64 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 2318 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2318 must float; the two are designed to be used as a pair.",
      "The 610/695 kN ratings and 8650 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2318?",
        "a": "A C 2318 measures 90 mm bore × 190 mm outside diameter × 64 mm width (3.543 × 7.48 × 2.52 in). From SKF catalogue PUB BU/P1 17000: dynamic C 610 kN, static C0 695 kN, fatigue limit Pu 73.5 kN, reference speed 2,800 r/min, limiting speed 4,000 r/min, mass about 8650 g."
      },
      {
        "q": "Can a CARB bearing like C 2318 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2318 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2318 designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 18 = 90 mm bore (code 18 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (610 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2318 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2318-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 90×190×64 mm ISO 15 envelope and equivalent catalogue C/C0; C 2318 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22318",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×190×64 mm) SKF spherical roller bearing SKF 22318 E with ratings within 10 % — not a drop-in substitute: SKF 22318 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22318-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×190×64 mm) SKF spherical roller bearing SKF 22318 EK with ratings within 10 % — not a drop-in substitute: SKF 22318 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2318",
      "C 2318"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2318-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2318 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 610,
    "static_load_kN": 695,
    "fatigue_load_limit_kN": 73.5,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "weight_g": 8650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2318 K belongs to the CARB family — compact aligning roller bearings: envelope 90×190×64 mm, radial rating 610/695 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (23) identify the ISO dimension series and the last two (18) encode the 90 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 90 mm shaft deflects; the 2,800 r/min reference and 4,000 r/min limiting speed are both catalogue values. Selection arithmetic: C 610 kN against C0 695 kN gives a C0/C ratio of 1.14, and the 73.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 64 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 64 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 610/695 kN ratings belong to this exact execution (C 2318 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 610/695 kN ratings and 8650 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2318 K have?",
        "a": "A C 2318 K measures 90 mm bore × 190 mm outside diameter × 64 mm width (3.543 × 7.48 × 2.52 in). From SKF catalogue PUB BU/P1 17000: dynamic C 610 kN, static C0 695 kN, fatigue limit Pu 73.5 kN, reference speed 2,800 r/min, limiting speed 4,000 r/min, mass about 8650 g."
      },
      {
        "q": "What does C 2318 K mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 90 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2318 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2318 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2318",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 90×190×64 mm ISO 15 envelope and equivalent catalogue C/C0; C 2318 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22318",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×190×64 mm) SKF spherical roller bearing SKF 22318 E with ratings within 10 % — not a drop-in substitute: SKF 22318 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22318-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (90×190×64 mm) SKF spherical roller bearing SKF 22318 EK with ratings within 10 % — not a drop-in substitute: SKF 22318 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2318-K",
      "C 2318 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2319",
    "brand": "SKF",
    "manufacturer_designation": "C 2319",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 610,
    "static_load_kN": 695,
    "fatigue_load_limit_kN": 73.5,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "weight_g": 10000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2319 in the dimension series 23 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (23) identify the ISO dimension series and the last two (19) encode the 95 mm bore; suffixes describe bore and execution. The cylindrical 95 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 95×200×67 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 67 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 95 mm seat or heat it (max 120 °C) and seat it square; never press through the 67 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 95 mm bore, shaft expansion is already measurable: calculate the required float inside the 67 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2319 must float; the two are designed to be used as a pair.",
      "Never use C 2319 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 95 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 610/695 kN ratings and 10000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2319 have?",
        "a": "A C 2319 measures 95 mm bore × 200 mm outside diameter × 67 mm width (3.74 × 7.874 × 2.638 in). From SKF catalogue PUB BU/P1 17000: dynamic C 610 kN, static C0 695 kN, fatigue limit Pu 73.5 kN, reference speed 2,800 r/min, limiting speed 4,000 r/min, mass about 10000 g."
      },
      {
        "q": "What does C 2319 mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 95 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2319 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2319-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 95×200×67 mm ISO 15 envelope and equivalent catalogue C/C0; C 2319 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22319",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×67 mm envelope as the SKF spherical roller bearing SKF 22319 E, but catalogue C/C0 differ (610/695 kN vs 699/765 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22319-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×67 mm envelope as the SKF spherical roller bearing SKF 22319 EK, but catalogue C/C0 differ (610/695 kN vs 699/765 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2319",
      "C 2319"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2319-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2319 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 610,
    "static_load_kN": 695,
    "fatigue_load_limit_kN": 73.5,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "weight_g": 10000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2319 K denotes a toroidal roller bearing whose 67 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 2319 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K. The K suffix gives a 1:12 tapered 95 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 95×200×67 mm are identical — only the mounting method changes. Selection arithmetic: C 610 kN against C0 695 kN gives a C0/C ratio of 1.14, and the 73.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 200 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 95 mm bore, shaft expansion is already measurable: calculate the required float inside the 67 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 95 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 2319 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 610/695 kN ratings belong to this exact execution (C 2319 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 610/695 kN ratings and 10000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2319 K have?",
        "a": "A C 2319 K measures 95 mm bore × 200 mm outside diameter × 67 mm width (3.74 × 7.874 × 2.638 in). From SKF catalogue PUB BU/P1 17000: dynamic C 610 kN, static C0 695 kN, fatigue limit Pu 73.5 kN, reference speed 2,800 r/min, limiting speed 4,000 r/min, mass about 10000 g."
      },
      {
        "q": "What does C 2319 K mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 95 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2319 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2319 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2319",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 95×200×67 mm ISO 15 envelope and equivalent catalogue C/C0; C 2319 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22319",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×67 mm envelope as the SKF spherical roller bearing SKF 22319 E, but catalogue C/C0 differ (610/695 kN vs 699/765 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22319-EK",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×67 mm envelope as the SKF spherical roller bearing SKF 22319 EK, but catalogue C/C0 differ (610/695 kN vs 699/765 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2319-K",
      "C 2319 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4020-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4020 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 150,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 355,
    "static_load_kN": 530,
    "fatigue_load_limit_kN": 58.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "weight_g": 3050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4020 V is the dimension series 40 CARB toroidal roller bearings member of the CARB range: 100 mm bore, 150 mm OD, 50 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 4020 V separates into C (CARB), 40 (dimension series), 20 (100 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 100×150×50 mm follows the ISO 15 plan. The V suffix denotes a full complement: the toroidal rollers fill the 50 mm space without a cage, raising C to 355 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4020 V deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 50 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 4020 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 100 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 355/530 kN ratings belong to this exact execution (C 4020 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 355/530 kN ratings and 3050 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 4020 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 100 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 50 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4020 V?",
        "a": "A C 4020 V measures 100 mm bore × 150 mm outside diameter × 50 mm width (3.937 × 5.906 × 1.969 in). From SKF catalogue PUB BU/P1 17000: dynamic C 355 kN, static C0 530 kN, fatigue limit Pu 58.5 kN, limiting speed 1,400 r/min, no reference speed listed, mass about 3050 g."
      },
      {
        "q": "Can a CARB bearing like C 4020 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4020 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4020 V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 20 = 100 mm bore (code 20 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24020",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×150×50 mm envelope as the SKF spherical roller bearing SKF 24020 CC/W33, but catalogue C/C0 differ (355/530 kN vs 296/415 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4020-V",
      "C 4020 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C5020-V",
    "brand": "SKF",
    "manufacturer_designation": "C 5020 V",
    "series": "C5000-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 150,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 510,
    "static_load_kN": 865,
    "fatigue_load_limit_kN": 95,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "weight_g": 4300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 5020 V denotes a toroidal roller bearing whose 67 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 5020 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 100 mm shaft deflects; no reference speed is listed and the limiting speed is 1,100 r/min. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 67 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 67 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 510/865 kN ratings belong to this exact execution (C 5020 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 5020 V must float; the two are designed to be used as a pair.",
      "Never use C 5020 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 510/865 kN ratings and 4300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 5020 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 5020 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 5020 V have?",
        "a": "A C 5020 V measures 100 mm bore × 150 mm outside diameter × 67 mm width (3.937 × 5.906 × 2.638 in). From SKF catalogue PUB BU/P1 17000: dynamic C 510 kN, static C0 865 kN, fatigue limit Pu 95 kN, limiting speed 1,100 r/min, no reference speed listed, mass about 4300 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C5020",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C5020-V",
      "C 5020 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3120-V",
    "brand": "SKF",
    "manufacturer_designation": "C 3120 V",
    "series": "C3100-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 165,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 475,
    "static_load_kN": 655,
    "fatigue_load_limit_kN": 71,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "weight_g": 4450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 3120 V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 100 mm bore, 165 mm outside diameter, 52 mm wide unit rated 475 kN dynamic. SKF builds the CARB order number from size plus execution: the bare number C 3120 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The V suffix denotes a full complement: the toroidal rollers fill the 52 mm space without a cage, raising C to 475 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Selection arithmetic: C 475 kN against C0 655 kN gives a C0/C ratio of 1.38, and the 71 kN fatigue load limit Pu sets the contamination-adjusted life floor. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 52 mm wide cavity does not fill itself.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 52 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 475/655 kN ratings belong to this exact execution (C 3120 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 3120 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 100 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 475/655 kN ratings and 4450 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 3120 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3120 V have?",
        "a": "A C 3120 V measures 100 mm bore × 165 mm outside diameter × 52 mm width (3.937 × 6.496 × 2.047 in). From SKF catalogue PUB BU/P1 17000: dynamic C 475 kN, static C0 655 kN, fatigue limit Pu 71 kN, limiting speed 1,300 r/min, no reference speed listed, mass about 4450 g."
      },
      {
        "q": "What does C 3120 V mean in SKF part numbering?",
        "a": "C marks CARB; 31 the dimension series; the size code gives 100 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "23120",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×165×52 mm envelope as the SKF spherical roller bearing SKF 23120 CC/W33, but catalogue C/C0 differ (475/655 kN vs 385/490 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23120-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×165×52 mm envelope as the SKF spherical roller bearing SKF 23120 CCK/W33, but catalogue C/C0 differ (475/655 kN vs 385/490 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3120-V",
      "C 3120 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4120-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4120-2CS5V/GEM9",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 165,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 475,
    "static_load_kN": 655,
    "fatigue_load_limit_kN": 69.5,
    "limiting_speed_rpm": 90,
    "max_rpm": 90,
    "weight_g": 5200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4120-2CS5V/GEM9 is the dimension series 41 CARB toroidal roller bearings member of the CARB range: 100 mm bore, 165 mm OD, 65 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. Reading the code: C marks the CARB toroidal family, the first two digits (41) identify the ISO dimension series and the last two (100 mm (slash-size)) encode the 100 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 100 mm seat. The 5200 g mass over the 100×165×65 mm envelope yields about 4.75 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Mounting: slide the bearing onto the 100 mm seat or heat it (max 120 °C) and seat it square; never press through the 65 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 65 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4120-2CS5V/GEM9 must float; the two are designed to be used as a pair.",
      "Never use C 4120-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 475/655 kN ratings belong to this exact execution (C 4120-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 475/655 kN ratings and 5200 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4120-2CS5V/GEM9 have?",
        "a": "A C 4120-2CS5V/GEM9 measures 100 mm bore × 165 mm outside diameter × 65 mm width (3.937 × 6.496 × 2.559 in). From SKF catalogue PUB BU/P1 17000: dynamic C 475 kN, static C0 655 kN, fatigue limit Pu 69.5 kN, limiting speed 90 r/min, no reference speed listed, mass about 5200 g."
      },
      {
        "q": "What does C 4120-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 41 the dimension series; the size code gives 100 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4120-2CS5V/GEM9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4120-V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 100×165×65 mm ISO 15 envelope and equivalent catalogue C/C0; C 4120 V/VE240 is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24120",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×165×65 mm) SKF spherical roller bearing SKF 24120 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24120 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4120-2CS5V-GEM9",
      "C 4120-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4120-V-VE240",
    "brand": "SKF",
    "manufacturer_designation": "C 4120 V/VE240",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 165,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 475,
    "static_load_kN": 655,
    "fatigue_load_limit_kN": 71,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "weight_g": 5300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 4120 V/VE240 denotes a toroidal roller bearing whose 65 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. In C 4120 V/VE240 the 41 dimension series fixes the 165 mm OD and 65 mm width around the 100 mm bore (the bore is written directly after the slash (no bore code)); the suffix V/VE240 then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 100 mm shaft deflects; no reference speed is listed and the limiting speed is 1,300 r/min. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4120 V/VE240 deliberately carries none. Mounting: slide the bearing onto the 100 mm seat or heat it (max 120 °C) and seat it square; never press through the 65 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 65 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4120 V/VE240 must float; the two are designed to be used as a pair.",
      "Never use C 4120 V/VE240 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 100 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 475/655 kN ratings and 5300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (475 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4120 V/VE240 is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4120 V/VE240 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 100 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 65 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4120 V/VE240?",
        "a": "A C 4120 V/VE240 measures 100 mm bore × 165 mm outside diameter × 65 mm width (3.937 × 6.496 × 2.559 in). From SKF catalogue PUB BU/P1 17000: dynamic C 475 kN, static C0 655 kN, fatigue limit Pu 71 kN, limiting speed 1,300 r/min, no reference speed listed, mass about 5300 g."
      },
      {
        "q": "Can a CARB bearing like C 4120 V/VE240 locate the shaft axially?",
        "a": "No — that is the defining feature. C 4120 V/VE240 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4120-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 100×165×65 mm ISO 15 envelope and equivalent catalogue C/C0; C 4120-2CS5V/GEM9 is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24120",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×165×65 mm) SKF spherical roller bearing SKF 24120 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24120 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4120-V-VE240",
      "C 4120 V/VE240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2220",
    "brand": "SKF",
    "manufacturer_designation": "C 2220",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 415,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 49,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 4950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2220 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 100×180×46 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 2220 separates into C (CARB), 22 (dimension series), 20 (100 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 100×180×46 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 100 mm seat. Selection arithmetic: C 415 kN against C0 465 kN gives a C0/C ratio of 1.12, and the 49 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: slide the bearing onto the 100 mm seat or heat it (max 120 °C) and seat it square; never press through the 46 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2220 must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 100 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 415/465 kN ratings and 4950 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 2220?",
        "a": "A C 2220 measures 100 mm bore × 180 mm outside diameter × 46 mm width (3.937 × 7.087 × 1.811 in). From SKF catalogue PUB BU/P1 17000: dynamic C 415 kN, static C0 465 kN, fatigue limit Pu 49 kN, reference speed 3,600 r/min, limiting speed 4,800 r/min, mass about 4950 g."
      },
      {
        "q": "Can a CARB bearing like C 2220 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2220 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2220 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 20 = 100 mm bore (code 20 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (415 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2220 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2220-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 100×180×46 mm ISO 15 envelope and equivalent catalogue C/C0; C 2220 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22220",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×180×46 mm) SKF spherical roller bearing SKF 22220 E with ratings within 10 % — not a drop-in substitute: SKF 22220 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22220-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×180×46 mm) SKF spherical roller bearing SKF 22220 EK with ratings within 10 % — not a drop-in substitute: SKF 22220 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2220",
      "C 2220"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2220-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2220 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 415,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 49,
    "reference_speed_rpm": 3600,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 4950,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2220 K denotes a toroidal roller bearing whose 46 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 2220 K separates into C (CARB), 22 (dimension series), 20 (100 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 100×180×46 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 100 mm shaft deflects; the 3,600 r/min reference and 4,800 r/min limiting speed are both catalogue values. Selection arithmetic: C 415 kN against C0 465 kN gives a C0/C ratio of 1.12, and the 49 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 46 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2220 K must float; the two are designed to be used as a pair.",
      "Never use C 2220 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 100 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 415/465 kN ratings and 4950 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (415 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2220 K is the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage."
      },
      {
        "q": "How is C 2220 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2220 K?",
        "a": "A C 2220 K measures 100 mm bore × 180 mm outside diameter × 46 mm width (3.937 × 7.087 × 1.811 in). From SKF catalogue PUB BU/P1 17000: dynamic C 415 kN, static C0 465 kN, fatigue limit Pu 49 kN, reference speed 3,600 r/min, limiting speed 4,800 r/min, mass about 4950 g."
      },
      {
        "q": "Can a CARB bearing like C 2220 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2220 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2220",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 100×180×46 mm ISO 15 envelope and equivalent catalogue C/C0; C 2220 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22220",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×180×46 mm) SKF spherical roller bearing SKF 22220 E with ratings within 10 % — not a drop-in substitute: SKF 22220 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22220-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×180×46 mm) SKF spherical roller bearing SKF 22220 EK with ratings within 10 % — not a drop-in substitute: SKF 22220 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2220-K",
      "C 2220 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2320",
    "brand": "SKF",
    "manufacturer_designation": "C 2320",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 800,
    "static_load_kN": 880,
    "fatigue_load_limit_kN": 90,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2320 belongs to the CARB family — compact aligning roller bearings: envelope 100×215×73 mm, radial rating 800/880 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (23) identify the ISO dimension series and the last two (20) encode the 100 mm bore; suffixes describe bore and execution. The cylindrical 100 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 100×215×73 mm are identical — only the mounting method changes. Speed planning separates the 2,600 r/min thermal reference from the 3,600 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: slide the bearing onto the 100 mm seat or heat it (max 120 °C) and seat it square; never press through the 73 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 73 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 800/880 kN ratings belong to this exact execution (C 2320); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 100 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 800/880 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 2320 have?",
        "a": "A C 2320 measures 100 mm bore × 215 mm outside diameter × 73 mm width (3.937 × 8.465 × 2.874 in). From SKF catalogue PUB BU/P1 17000: dynamic C 800 kN, static C0 880 kN, fatigue limit Pu 90 kN, reference speed 2,600 r/min, limiting speed 3,600 r/min, mass about 12500 g."
      },
      {
        "q": "What does C 2320 mean in SKF part numbering?",
        "a": "C marks CARB; 23 the dimension series; the size code gives 100 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2320 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2320 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2320-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 100×215×73 mm ISO 15 envelope and equivalent catalogue C/C0; C 2320 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22320",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×215×73 mm) SKF spherical roller bearing SKF 22320 E with ratings within 10 % — not a drop-in substitute: SKF 22320 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22320-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×215×73 mm) SKF spherical roller bearing SKF 22320 EK with ratings within 10 % — not a drop-in substitute: SKF 22320 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2320",
      "C 2320"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2320-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2320 K",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 800,
    "static_load_kN": 880,
    "fatigue_load_limit_kN": 90,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2320 K: the toroidal rollers allow the 100 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. The designation C 2320 K separates into C (CARB), 23 (dimension series), 20 (100 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 100×215×73 mm follows the ISO 15 plan. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 100×215 mm size with 800 kN dynamic and a 2,600 r/min reference speed. The 12500 g mass over the 100×215×73 mm envelope yields about 8.00 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 73 mm wide cavity does not fill itself.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 100 mm bore, shaft expansion is already measurable: calculate the required float inside the 73 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 2,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 800/880 kN ratings belong to this exact execution (C 2320 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2320 K must float; the two are designed to be used as a pair.",
      "The 800/880 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2320 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2320 K?",
        "a": "A C 2320 K measures 100 mm bore × 215 mm outside diameter × 73 mm width (3.937 × 8.465 × 2.874 in). From SKF catalogue PUB BU/P1 17000: dynamic C 800 kN, static C0 880 kN, fatigue limit Pu 90 kN, reference speed 2,600 r/min, limiting speed 3,600 r/min, mass about 12500 g."
      },
      {
        "q": "Can a CARB bearing like C 2320 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2320 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2320 K designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 20 = 100 mm bore (code 20 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2320",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 100×215×73 mm ISO 15 envelope and equivalent catalogue C/C0; C 2320 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22320",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×215×73 mm) SKF spherical roller bearing SKF 22320 E with ratings within 10 % — not a drop-in substitute: SKF 22320 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22320-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (100×215×73 mm) SKF spherical roller bearing SKF 22320 EK with ratings within 10 % — not a drop-in substitute: SKF 22320 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2320-K",
      "C 2320 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4022-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4022-2CS5V/GEM9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 170,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 415,
    "static_load_kN": 585,
    "fatigue_load_limit_kN": 63,
    "limiting_speed_rpm": 85,
    "max_rpm": 85,
    "weight_g": 4600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 4022-2CS5V/GEM9: the toroidal rollers allow the 110 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. In C 4022-2CS5V/GEM9 the 40 dimension series fixes the 170 mm OD and 60 mm width around the 110 mm bore (the bore is written directly after the slash (no bore code)); the suffix 2CS5V/GEM9 then selects the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. The 2CS5V/GEM9 execution adds nitrile contact seals on both sides plus an annular-groove relubrication feature and a high-viscosity grease fill; the full-complement rollers keep 415 kN dynamic at a reduced 85 r/min ceiling. The 4600 g mass over the 110×170×60 mm envelope yields about 3.77 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 415/585 kN ratings belong to this exact execution (C 4022-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4022-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 110 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 415/585 kN ratings and 4600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 4022-2CS5V/GEM9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 110 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 60 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4022-2CS5V/GEM9?",
        "a": "A C 4022-2CS5V/GEM9 measures 110 mm bore × 170 mm outside diameter × 60 mm width (4.331 × 6.693 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 415 kN, static C0 585 kN, fatigue limit Pu 63 kN, limiting speed 85 r/min, no reference speed listed, mass about 4600 g."
      },
      {
        "q": "Can a CARB bearing like C 4022-2CS5V/GEM9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 4022-2CS5V/GEM9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4022-2CS5V/GEM9 designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 110 mm (slash-size) = 110 mm bore (the bore is written directly after the slash (no bore code)); suffix 2CS5V/GEM9 selects cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4022-MB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore MB inner-ring-guided brass-caged executions (415/585 kN vs 430/655 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4022-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (415/585 kN vs 500/800 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24022",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×170×60 mm) SKF spherical roller bearing SKF 24022 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24022 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4022-2CS5V-GEM9",
      "C 4022-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4022-MB",
    "brand": "SKF",
    "manufacturer_designation": "C 4022 MB",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 170,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 430,
    "static_load_kN": 655,
    "fatigue_load_limit_kN": 69.5,
    "reference_speed_rpm": 2600,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "weight_g": 5300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 4022 MB denotes a toroidal roller bearing whose 60 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 4022 is the brass-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here MB. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 110 mm shaft deflects; the 2,600 r/min reference and 3,400 r/min limiting speed are both catalogue values. Selection arithmetic: C 430 kN against C0 655 kN gives a C0/C ratio of 1.52, and the 69.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 60 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4022 MB must float; the two are designed to be used as a pair.",
      "Never use C 4022 MB as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 110 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,600 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 430/655 kN ratings and 5300 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4022 MB have?",
        "a": "A C 4022 MB measures 110 mm bore × 170 mm outside diameter × 60 mm width (4.331 × 6.693 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 430 kN, static C0 655 kN, fatigue limit Pu 69.5 kN, reference speed 2,600 r/min, limiting speed 3,400 r/min, mass about 5300 g."
      },
      {
        "q": "What does C 4022 MB mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 110 mm bore; MB is the execution (cylindrical bore for direct shaft fitting, machined inner-ring-guided brass cage (MB)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4022 MB used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4022 MB sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4022-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore sealed full-complement V executions (430/655 kN vs 415/585 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4022-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore full-complement V executions (430/655 kN vs 500/800 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24022",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×170×60 mm) SKF spherical roller bearing SKF 24022 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24022 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4022-MB",
      "C 4022 MB"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4022-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4022 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 170,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 500,
    "static_load_kN": 800,
    "fatigue_load_limit_kN": 85,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "weight_g": 5200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4022 V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 110×170×60 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. In C 4022 V the 40 dimension series fixes the 170 mm OD and 60 mm width around the 110 mm bore (code 22 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 110 mm shaft deflects; no reference speed is listed and the limiting speed is 1,200 r/min. The 5200 g mass over the 110×170×60 mm envelope yields about 4.55 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 170 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4022 V must float; the two are designed to be used as a pair.",
      "The quoted 500/800 kN ratings belong to this exact execution (C 4022 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4022 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 500/800 kN ratings and 5200 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 4022 V?",
        "a": "A C 4022 V measures 110 mm bore × 170 mm outside diameter × 60 mm width (4.331 × 6.693 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 500 kN, static C0 800 kN, fatigue limit Pu 85 kN, limiting speed 1,200 r/min, no reference speed listed, mass about 5200 g."
      },
      {
        "q": "Can a CARB bearing like C 4022 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4022 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4022 V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 22 = 110 mm bore (code 22 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (500 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4022 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4022-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (500/800 kN vs 415/585 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4022-MB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore MB inner-ring-guided brass-caged executions (500/800 kN vs 430/655 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24022",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×170×60 mm envelope as the SKF spherical roller bearing SKF 24022 CC/W33, but catalogue C/C0 differ (500/800 kN vs 437/620 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4022-V",
      "C 4022 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4122-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4122-2CS5V/GEM9",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 180,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 500,
    "static_load_kN": 710,
    "fatigue_load_limit_kN": 75,
    "limiting_speed_rpm": 80,
    "max_rpm": 80,
    "weight_g": 6600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4122-2CS5V/GEM9 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 110×180×69 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. In C 4122-2CS5V/GEM9 the 41 dimension series fixes the 180 mm OD and 69 mm width around the 110 mm bore (the bore is written directly after the slash (no bore code)); the suffix 2CS5V/GEM9 then selects the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. Both-side contact seals protect the full-complement roller set in contaminated housings, with grease for life at fitting. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 110 mm shaft deflects; no reference speed is listed and the limiting speed is 80 r/min. The 6600 g mass over the 110×180×69 mm envelope yields about 4.55 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 180 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 500/710 kN ratings belong to this exact execution (C 4122-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 4122-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 500/710 kN ratings and 6600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 4122-2CS5V/GEM9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 110 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 69 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4122-2CS5V/GEM9?",
        "a": "A C 4122-2CS5V/GEM9 measures 110 mm bore × 180 mm outside diameter × 69 mm width (4.331 × 7.087 × 2.717 in). From SKF catalogue PUB BU/P1 17000: dynamic C 500 kN, static C0 710 kN, fatigue limit Pu 75 kN, limiting speed 80 r/min, no reference speed listed, mass about 6600 g."
      },
      {
        "q": "Can a CARB bearing like C 4122-2CS5V/GEM9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 4122-2CS5V/GEM9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4122-2CS5V/GEM9 designation read?",
        "a": "C = CARB toroidal family; 41 = dimension series; 110 mm (slash-size) = 110 mm bore (the bore is written directly after the slash (no bore code)); suffix 2CS5V/GEM9 selects cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4122-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×180×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (500/710 kN vs 670/1000 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24122",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×180×69 mm) SKF spherical roller bearing SKF 24122 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24122 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24122-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×180×69 mm) SKF spherical roller bearing SKF 24122 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24122 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4122-2CS5V-GEM9",
      "C 4122-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4122-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4122 V",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 180,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 670,
    "static_load_kN": 1000,
    "fatigue_load_limit_kN": 104,
    "limiting_speed_rpm": 900,
    "max_rpm": 900,
    "weight_g": 7100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 4122 V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 110 mm bore, 180 mm outside diameter, 69 mm wide unit rated 670 kN dynamic. In C 4122 V the 41 dimension series fixes the 180 mm OD and 69 mm width around the 110 mm bore (code 22 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The V suffix denotes a full complement: the toroidal rollers fill the 69 mm space without a cage, raising C to 670 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4122 V deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 670/1000 kN ratings belong to this exact execution (C 4122 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4122 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 110 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 670/1000 kN ratings and 7100 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 4122 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4122 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4122 V designation read?",
        "a": "C = CARB toroidal family; 41 = dimension series; 22 = 110 mm bore (code 22 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (670 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4122 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4122 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 110 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 69 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4122-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×180×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (670/1000 kN vs 500/710 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24122",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×180×69 mm envelope as the SKF spherical roller bearing SKF 24122 CC/W33, but catalogue C/C0 differ (670/1000 kN vs 539/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24122-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×180×69 mm envelope as the SKF spherical roller bearing SKF 24122 CCK30/W33, but catalogue C/C0 differ (670/1000 kN vs 539/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4122-V",
      "C 4122 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2222",
    "brand": "SKF",
    "manufacturer_designation": "C 2222",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 530,
    "static_load_kN": 620,
    "fatigue_load_limit_kN": 64,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 7000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2222 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 110 mm bore, 200 mm outside diameter, 53 mm wide unit rated 530 kN dynamic. In C 2222 the 22 dimension series fixes the 200 mm OD and 53 mm width around the 110 mm bore (code 22 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 110 mm seat. Selection arithmetic: C 530 kN against C0 620 kN gives a C0/C ratio of 1.17, and the 64 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 200 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 53 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 3,200 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 530/620 kN ratings belong to this exact execution (C 2222); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2222 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 530/620 kN ratings and 7000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (530 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2222 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 2222 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 110 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 53 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2222?",
        "a": "A C 2222 measures 110 mm bore × 200 mm outside diameter × 53 mm width (4.331 × 7.874 × 2.087 in). From SKF catalogue PUB BU/P1 17000: dynamic C 530 kN, static C0 620 kN, fatigue limit Pu 64 kN, reference speed 3,200 r/min, limiting speed 4,300 r/min, mass about 7000 g."
      },
      {
        "q": "Can a CARB bearing like C 2222 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2222 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2222-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 110×200×53 mm ISO 15 envelope and equivalent catalogue C/C0; C 2222 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22222",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×200×53 mm) SKF spherical roller bearing SKF 22222 E with ratings within 10 % — not a drop-in substitute: SKF 22222 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22222-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×200×53 mm) SKF spherical roller bearing SKF 22222 EK with ratings within 10 % — not a drop-in substitute: SKF 22222 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2222",
      "C 2222"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2222-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2222 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 530,
    "static_load_kN": 620,
    "fatigue_load_limit_kN": 64,
    "reference_speed_rpm": 3200,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 7000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2222 K belongs to the CARB family — compact aligning roller bearings: envelope 110×200×53 mm, radial rating 530/620 kN C/C0, and no axial-locating function by design. SKF builds the CARB order number from size plus execution: the bare number C 2222 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K. The K suffix gives a 1:12 tapered 110 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 110×200×53 mm are identical — only the mounting method changes. Speed planning separates the 3,200 r/min thermal reference from the 4,300 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 53 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 110 mm bore, shaft expansion is already measurable: calculate the required float inside the 53 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 110 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 3,200 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2222 K must float; the two are designed to be used as a pair.",
      "Never use C 2222 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 530/620 kN ratings and 7000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2222 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2222 K have?",
        "a": "A C 2222 K measures 110 mm bore × 200 mm outside diameter × 53 mm width (4.331 × 7.874 × 2.087 in). From SKF catalogue PUB BU/P1 17000: dynamic C 530 kN, static C0 620 kN, fatigue limit Pu 64 kN, reference speed 3,200 r/min, limiting speed 4,300 r/min, mass about 7000 g."
      },
      {
        "q": "What does C 2222 K mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 110 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2222",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 110×200×53 mm ISO 15 envelope and equivalent catalogue C/C0; C 2222 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22222",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×200×53 mm) SKF spherical roller bearing SKF 22222 E with ratings within 10 % — not a drop-in substitute: SKF 22222 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22222-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (110×200×53 mm) SKF spherical roller bearing SKF 22222 EK with ratings within 10 % — not a drop-in substitute: SKF 22222 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2222-K",
      "C 2222 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3024-V",
    "brand": "SKF",
    "manufacturer_designation": "C 3024 V",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 430,
    "static_load_kN": 640,
    "fatigue_load_limit_kN": 65.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "weight_g": 4100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3024 V belongs to the CARB family — compact aligning roller bearings: envelope 120×180×46 mm, radial rating 430/640 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (24) encode the 120 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 120 mm shaft deflects; no reference speed is listed and the limiting speed is 1,400 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 1,400 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 46 mm wide cavity does not fill itself.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3024 V must float; the two are designed to be used as a pair.",
      "Never use C 3024 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 430/640 kN ratings belong to this exact execution (C 3024 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 430/640 kN ratings and 4100 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 3024 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3024 V have?",
        "a": "A C 3024 V measures 120 mm bore × 180 mm outside diameter × 46 mm width (4.724 × 7.087 × 1.811 in). From SKF catalogue PUB BU/P1 17000: dynamic C 430 kN, static C0 640 kN, fatigue limit Pu 65.5 kN, limiting speed 1,400 r/min, no reference speed listed, mass about 4100 g."
      },
      {
        "q": "What does C 3024 V mean in SKF part numbering?",
        "a": "C marks CARB; 30 the dimension series; the size code gives 120 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "23024",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×46 mm envelope as the SKF spherical roller bearing SKF 23024 CC/W33, but catalogue C/C0 differ (430/640 kN vs 366/500 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23024-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×46 mm envelope as the SKF spherical roller bearing SKF 23024 CCK/W33, but catalogue C/C0 differ (430/640 kN vs 366/500 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3024-V",
      "C 3024 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4024-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4024-2CS5V/GEM9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 430,
    "static_load_kN": 640,
    "fatigue_load_limit_kN": 67,
    "limiting_speed_rpm": 80,
    "max_rpm": 80,
    "weight_g": 5100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4024-2CS5V/GEM9 is the dimension series 40 CARB toroidal roller bearings member of the CARB range: 120 mm bore, 180 mm OD, 60 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. In C 4024-2CS5V/GEM9 the 40 dimension series fixes the 180 mm OD and 60 mm width around the 120 mm bore (the bore is written directly after the slash (no bore code)); the suffix 2CS5V/GEM9 then selects the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. The cylindrical 120 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 120×180×60 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 60 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Sealed executions arrive greased for life: do not wash out the factory fill, and mount seals-clear of the housing shoulder edges. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 60 mm wide cavity does not fill itself.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 4024-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 430/640 kN ratings belong to this exact execution (C 4024-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 430/640 kN ratings and 5100 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 4024-2CS5V/GEM9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 120 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 60 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4024-2CS5V/GEM9?",
        "a": "A C 4024-2CS5V/GEM9 measures 120 mm bore × 180 mm outside diameter × 60 mm width (4.724 × 7.087 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 430 kN, static C0 640 kN, fatigue limit Pu 67 kN, limiting speed 80 r/min, no reference speed listed, mass about 5100 g."
      },
      {
        "q": "Can a CARB bearing like C 4024-2CS5V/GEM9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 4024-2CS5V/GEM9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4024-2CS5V/GEM9 designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 120 mm (slash-size) = 120 mm bore (the bore is written directly after the slash (no bore code)); suffix 2CS5V/GEM9 selects cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4024-V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024 V/VE240 is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4024-K30V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024 K30V/VE240 is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4024-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (430/640 kN vs 530/880 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and 1:30 tapered-bore K30 full-complement V executions (430/640 kN vs 530/880 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24024",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×180×60 mm) SKF spherical roller bearing SKF 24024 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24024 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24024-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×180×60 mm) SKF spherical roller bearing SKF 24024 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24024 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4024-2CS5V-GEM9",
      "C 4024-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4024-V-VE240",
    "brand": "SKF",
    "manufacturer_designation": "C 4024 V/VE240",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 430,
    "static_load_kN": 640,
    "fatigue_load_limit_kN": 65.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "weight_g": 5050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 4024 V/VE240: the toroidal rollers allow the 120 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (120 mm (slash-size)) encode the 120 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 120 mm shaft deflects; no reference speed is listed and the limiting speed is 1,400 r/min. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 60 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 60 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 430/640 kN ratings belong to this exact execution (C 4024 V/VE240); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 4024 V/VE240 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 430/640 kN ratings and 5050 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 4024 V/VE240 sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4024 V/VE240 have?",
        "a": "A C 4024 V/VE240 measures 120 mm bore × 180 mm outside diameter × 60 mm width (4.724 × 7.087 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 430 kN, static C0 640 kN, fatigue limit Pu 65.5 kN, limiting speed 1,400 r/min, no reference speed listed, mass about 5050 g."
      },
      {
        "q": "What does C 4024 V/VE240 mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 120 mm bore; V/VE240 is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4024-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024-2CS5V/GEM9 is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4024-K30V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024 K30V/VE240 is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4024-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore full-complement V executions (430/640 kN vs 530/880 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:30 tapered-bore K30 full-complement V executions (430/640 kN vs 530/880 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24024",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×180×60 mm) SKF spherical roller bearing SKF 24024 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24024 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24024-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×180×60 mm) SKF spherical roller bearing SKF 24024 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24024 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4024-V-VE240",
      "C 4024 V/VE240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4024-K30V-VE240",
    "brand": "SKF",
    "manufacturer_designation": "C 4024 K30V/VE240",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 430,
    "static_load_kN": 640,
    "fatigue_load_limit_kN": 65.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "weight_g": 5050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4024 K30V/VE240 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 120×180×60 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. SKF builds the CARB order number from size plus execution: the bare number C 4024 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K30V/VE240. The K30 suffix gives a 1:30 tapered 120 mm bore, mounted on a withdrawal (AH) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 120×180×60 mm are identical — only the mounting method changes. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 1,400 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: mount on the withdrawal (AH) sleeve matched to the 1:30 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 60 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 430/640 kN ratings belong to this exact execution (C 4024 K30V/VE240); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 430/640 kN ratings and 5050 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 4024 K30V/VE240 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4024 K30V/VE240 sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4024 K30V/VE240 have?",
        "a": "A C 4024 K30V/VE240 measures 120 mm bore × 180 mm outside diameter × 60 mm width (4.724 × 7.087 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 430 kN, static C0 640 kN, fatigue limit Pu 65.5 kN, limiting speed 1,400 r/min, no reference speed listed, mass about 5050 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4024-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024-2CS5V/GEM9 is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4024-V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024 V/VE240 is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4024-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore full-complement V executions (430/640 kN vs 530/880 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and 1:30 tapered-bore K30 full-complement V executions (430/640 kN vs 530/880 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24024",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×180×60 mm) SKF spherical roller bearing SKF 24024 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24024 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24024-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×180×60 mm) SKF spherical roller bearing SKF 24024 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24024 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4024-K30V-VE240",
      "C 4024 K30V/VE240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4024-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4024 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 530,
    "static_load_kN": 880,
    "fatigue_load_limit_kN": 91.5,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "weight_g": 5550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4024 V in the dimension series 40 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (24) encode the 120 mm bore; suffixes describe bore and execution. The cylindrical 120 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 120×180×60 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 60 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 180 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 530/880 kN ratings belong to this exact execution (C 4024 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 530/880 kN ratings and 5550 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4024 V have?",
        "a": "A C 4024 V measures 120 mm bore × 180 mm outside diameter × 60 mm width (4.724 × 7.087 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 530 kN, static C0 880 kN, fatigue limit Pu 91.5 kN, limiting speed 1,100 r/min, no reference speed listed, mass about 5550 g."
      },
      {
        "q": "What does C 4024 V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 120 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4024 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4024 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4024-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (530/880 kN vs 430/640 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-V-VE240",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore full-complement V executions (530/880 kN vs 430/640 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-K30V-VE240",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:30 tapered-bore K30 full-complement V executions (530/880 kN vs 430/640 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-K30V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024 K30V is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24024",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope as the SKF spherical roller bearing SKF 24024 CC/W33, but catalogue C/C0 differ (530/880 kN vs 456/670 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24024-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope as the SKF spherical roller bearing SKF 24024 CCK30/W33, but catalogue C/C0 differ (530/880 kN vs 456/670 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4024-V",
      "C 4024 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4024-K30V",
    "brand": "SKF",
    "manufacturer_designation": "C 4024 K30V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 530,
    "static_load_kN": 880,
    "fatigue_load_limit_kN": 91.5,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "weight_g": 5550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4024 K30V in the dimension series 40 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. In C 4024 K30V the 40 dimension series fixes the 180 mm OD and 60 mm width around the 120 mm bore (code 24 × 5); the suffix K30V then selects the tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage). The K30 suffix gives a 1:30 tapered 120 mm bore, mounted on a withdrawal (AH) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 120×180×60 mm are identical — only the mounting method changes. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4024 K30V deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 60 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4024 K30V must float; the two are designed to be used as a pair.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 530/880 kN ratings belong to this exact execution (C 4024 K30V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 530/880 kN ratings and 5550 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 4024 K30V?",
        "a": "A C 4024 K30V measures 120 mm bore × 180 mm outside diameter × 60 mm width (4.724 × 7.087 × 2.362 in). From SKF catalogue PUB BU/P1 17000: dynamic C 530 kN, static C0 880 kN, fatigue limit Pu 91.5 kN, limiting speed 1,100 r/min, no reference speed listed, mass about 5550 g."
      },
      {
        "q": "Can a CARB bearing like C 4024 K30V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4024 K30V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4024 K30V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 24 = 120 mm bore (code 24 × 5); suffix K30V selects tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (530 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4024 K30V is the tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4024-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore sealed full-complement V executions (530/880 kN vs 430/640 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-V-VE240",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore full-complement V executions (530/880 kN vs 430/640 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-K30V-VE240",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and 1:30 tapered-bore K30 full-complement V executions (530/880 kN vs 430/640 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4024-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×180×60 mm ISO 15 envelope and equivalent catalogue C/C0; C 4024 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24024",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope as the SKF spherical roller bearing SKF 24024 CC/W33, but catalogue C/C0 differ (530/880 kN vs 456/670 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24024-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×60 mm envelope as the SKF spherical roller bearing SKF 24024 CCK30/W33, but catalogue C/C0 differ (530/880 kN vs 456/670 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4024-K30V",
      "C 4024 K30V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4124-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4124 V",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 200,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 780,
    "static_load_kN": 1120,
    "fatigue_load_limit_kN": 114,
    "limiting_speed_rpm": 750,
    "max_rpm": 750,
    "weight_g": 10000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 4124 V denotes a toroidal roller bearing whose 80 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 4124 V separates into C (CARB), 41 (dimension series), 24 (120 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 120×200×80 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 120 mm seat. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 750 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 4124 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 780/1120 kN ratings belong to this exact execution (C 4124 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 780/1120 kN ratings and 10000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 4124 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4124 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4124 V designation read?",
        "a": "C = CARB toroidal family; 41 = dimension series; 24 = 120 mm bore (code 24 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (780 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4124 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4124 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 120 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 80 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24124",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×200×80 mm envelope as the SKF spherical roller bearing SKF 24124 CC/W33, but catalogue C/C0 differ (780/1120 kN vs 679/950 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24124-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×200×80 mm envelope as the SKF spherical roller bearing SKF 24124 CCK30/W33, but catalogue C/C0 differ (780/1120 kN vs 679/950 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4124-V",
      "C 4124 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3224",
    "brand": "SKF",
    "manufacturer_designation": "C 3224",
    "series": "C3200-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 76,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 750,
    "static_load_kN": 980,
    "fatigue_load_limit_kN": 98,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 12000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3224 belongs to the CARB family — compact aligning roller bearings: envelope 120×215×76 mm, radial rating 750/980 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (32) identify the ISO dimension series and the last two (24) encode the 120 mm bore; suffixes describe bore and execution. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 120 mm shaft deflects; the 2,400 r/min reference and 3,200 r/min limiting speed are both catalogue values. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 3224 deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 215 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 76 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 750/980 kN ratings belong to this exact execution (C 3224); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 750/980 kN ratings and 12000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 3224 mean in SKF part numbering?",
        "a": "C marks CARB; 32 the dimension series; the size code gives 120 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 3224 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3224 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3224-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×215×76 mm ISO 15 envelope and equivalent catalogue C/C0; C 3224 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23224",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×215×76 mm) SKF spherical roller bearing SKF 23224 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23224 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23224-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×215×76 mm) SKF spherical roller bearing SKF 23224 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23224 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3224",
      "C 3224"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3224-K",
    "brand": "SKF",
    "manufacturer_designation": "C 3224 K",
    "series": "C3200-series",
    "type": "carb_toroidal",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 76,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 750,
    "static_load_kN": 980,
    "fatigue_load_limit_kN": 98,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 12000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3224 K belongs to the CARB family — compact aligning roller bearings: envelope 120×215×76 mm, radial rating 750/980 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (32) identify the ISO dimension series and the last two (24) encode the 120 mm bore; suffixes describe bore and execution. The K suffix gives a 1:12 tapered 120 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 120×215×76 mm are identical — only the mounting method changes. Speed planning separates the 2,400 r/min thermal reference from the 3,200 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 215 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 76 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 3224 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 750/980 kN ratings belong to this exact execution (C 3224 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 750/980 kN ratings and 12000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 3224 K mean in SKF part numbering?",
        "a": "C marks CARB; 32 the dimension series; the size code gives 120 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 3224 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3224 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3224",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 120×215×76 mm ISO 15 envelope and equivalent catalogue C/C0; C 3224 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23224",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×215×76 mm) SKF spherical roller bearing SKF 23224 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23224 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23224-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (120×215×76 mm) SKF spherical roller bearing SKF 23224 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23224 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3224-K",
      "C 3224 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4026-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4026-2CS5V/GEM9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 550,
    "static_load_kN": 830,
    "fatigue_load_limit_kN": 85,
    "limiting_speed_rpm": 70,
    "max_rpm": 70,
    "weight_g": 7500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4026-2CS5V/GEM9 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 130×200×69 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. In C 4026-2CS5V/GEM9 the 40 dimension series fixes the 200 mm OD and 69 mm width around the 130 mm bore (the bore is written directly after the slash (no bore code)); the suffix 2CS5V/GEM9 then selects the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove. The cylindrical 130 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 130×200×69 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 69 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 130 mm seat or heat it (max 120 °C) and seat it square; never press through the 69 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4026-2CS5V/GEM9 must float; the two are designed to be used as a pair.",
      "Never use C 4026-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 130 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 550/830 kN ratings and 7500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (550 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4026-2CS5V/GEM9 is the cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove."
      },
      {
        "q": "How is C 4026-2CS5V/GEM9 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 130 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 69 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4026-2CS5V/GEM9?",
        "a": "A C 4026-2CS5V/GEM9 measures 130 mm bore × 200 mm outside diameter × 69 mm width (5.118 × 7.874 × 2.717 in). From SKF catalogue PUB BU/P1 17000: dynamic C 550 kN, static C0 830 kN, fatigue limit Pu 85 kN, limiting speed 70 r/min, no reference speed listed, mass about 7500 g."
      },
      {
        "q": "Can a CARB bearing like C 4026-2CS5V/GEM9 locate the shaft axially?",
        "a": "No — that is the defining feature. C 4026-2CS5V/GEM9 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore steel-caged executions (550/830 kN vs 620/930 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and 1:30 tapered-bore K30 steel-caged executions (550/830 kN vs 620/930 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (550/830 kN vs 720/1120 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and 1:30 tapered-bore K30 full-complement V executions (550/830 kN vs 720/1120 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24026",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×200×69 mm) SKF spherical roller bearing SKF 24026 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24026 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24026-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×200×69 mm) SKF spherical roller bearing SKF 24026 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24026 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4026-2CS5V-GEM9",
      "C 4026-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4026",
    "brand": "SKF",
    "manufacturer_designation": "C 4026",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 620,
    "static_load_kN": 930,
    "fatigue_load_limit_kN": 93,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 7850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 4026 denotes a toroidal roller bearing whose 69 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (26) encode the 130 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 130 mm seat. Speed planning separates the 2,200 r/min thermal reference from the 2,800 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 69 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 620/930 kN ratings belong to this exact execution (C 4026); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Reference and limiting speeds are different limits: the 2,200 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 4026 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 620/930 kN ratings and 7850 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 4026 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4026 have?",
        "a": "A C 4026 measures 130 mm bore × 200 mm outside diameter × 69 mm width (5.118 × 7.874 × 2.717 in). From SKF catalogue PUB BU/P1 17000: dynamic C 620 kN, static C0 930 kN, fatigue limit Pu 93 kN, reference speed 2,200 r/min, limiting speed 2,800 r/min, mass about 7850 g."
      },
      {
        "q": "What does C 4026 mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 130 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4026-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and cylindrical-bore sealed full-complement V executions (620/930 kN vs 550/830 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 130×200×69 mm ISO 15 envelope and equivalent catalogue C/C0; C 4026 K30 is the 1:30 tapered-bore K30 steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4026-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and cylindrical-bore full-complement V executions (620/930 kN vs 720/1120 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and 1:30 tapered-bore K30 full-complement V executions (620/930 kN vs 720/1120 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CC/W33, but catalogue C/C0 differ (620/930 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24026-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CCK30/W33, but catalogue C/C0 differ (620/930 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4026",
      "C 4026"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4026-K30",
    "brand": "SKF",
    "manufacturer_designation": "C 4026 K30",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 620,
    "static_load_kN": 930,
    "fatigue_load_limit_kN": 93,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 7850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 4026 K30 denotes a toroidal roller bearing whose 69 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (26) encode the 130 mm bore; suffixes describe bore and execution. The K30 suffix gives a 1:30 tapered 130 mm bore, mounted on a withdrawal (AH) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 130×200×69 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 69 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 69 mm wide cavity does not fill itself.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 620/930 kN ratings belong to this exact execution (C 4026 K30); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4026 K30 must float; the two are designed to be used as a pair.",
      "Never use C 4026 K30 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 620/930 kN ratings and 7850 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4026 K30 have?",
        "a": "A C 4026 K30 measures 130 mm bore × 200 mm outside diameter × 69 mm width (5.118 × 7.874 × 2.717 in). From SKF catalogue PUB BU/P1 17000: dynamic C 620 kN, static C0 930 kN, fatigue limit Pu 93 kN, reference speed 2,200 r/min, limiting speed 2,800 r/min, mass about 7850 g."
      },
      {
        "q": "What does C 4026 K30 mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 130 mm bore; K30 is the execution (tapered 1:30 bore for withdrawal (AH) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4026 K30 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4026-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 steel-caged and cylindrical-bore sealed full-complement V executions (620/930 kN vs 550/830 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 130×200×69 mm ISO 15 envelope and equivalent catalogue C/C0; C 4026 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4026-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 steel-caged and cylindrical-bore full-complement V executions (620/930 kN vs 720/1120 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 steel-caged and 1:30 tapered-bore K30 full-complement V executions (620/930 kN vs 720/1120 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CC/W33, but catalogue C/C0 differ (620/930 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24026-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CCK30/W33, but catalogue C/C0 differ (620/930 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4026-K30",
      "C 4026 K30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4026-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4026 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 720,
    "static_load_kN": 1120,
    "fatigue_load_limit_kN": 112,
    "limiting_speed_rpm": 850,
    "max_rpm": 850,
    "weight_g": 8150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 4026 V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 130 mm bore, 200 mm outside diameter, 69 mm wide unit rated 720 kN dynamic. SKF builds the CARB order number from size plus execution: the bare number C 4026 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The V suffix denotes a full complement: the toroidal rollers fill the 69 mm space without a cage, raising C to 720 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 850 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 69 mm wide cavity does not fill itself.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4026 V must float; the two are designed to be used as a pair.",
      "Never use C 4026 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 130 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 720/1120 kN ratings and 8150 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 4026 V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 130 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4026 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4026 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4026-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (720/1120 kN vs 550/830 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore steel-caged executions (720/1120 kN vs 620/930 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:30 tapered-bore K30 steel-caged executions (720/1120 kN vs 620/930 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 130×200×69 mm ISO 15 envelope and equivalent catalogue C/C0; C 4026 K30V is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CC/W33, but catalogue C/C0 differ (720/1120 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24026-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CCK30/W33, but catalogue C/C0 differ (720/1120 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4026-V",
      "C 4026 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4026-K30V",
    "brand": "SKF",
    "manufacturer_designation": "C 4026 K30V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 720,
    "static_load_kN": 1120,
    "fatigue_load_limit_kN": 112,
    "limiting_speed_rpm": 850,
    "max_rpm": 850,
    "weight_g": 8150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 4026 K30V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 130 mm bore, 200 mm outside diameter, 69 mm wide unit rated 720 kN dynamic. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (26) encode the 130 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 130 mm seat. Selection arithmetic: C 720 kN against C0 1120 kN gives a C0/C ratio of 1.56, and the 112 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: mount on the withdrawal (AH) sleeve matched to the 1:30 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 69 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 720/1120 kN ratings belong to this exact execution (C 4026 K30V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4026 K30V must float; the two are designed to be used as a pair.",
      "Never use C 4026 K30V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 720/1120 kN ratings and 8150 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4026 K30V have?",
        "a": "A C 4026 K30V measures 130 mm bore × 200 mm outside diameter × 69 mm width (5.118 × 7.874 × 2.717 in). From SKF catalogue PUB BU/P1 17000: dynamic C 720 kN, static C0 1120 kN, fatigue limit Pu 112 kN, limiting speed 850 r/min, no reference speed listed, mass about 8150 g."
      },
      {
        "q": "What does C 4026 K30V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 130 mm bore; K30V is the execution (tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4026 K30V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4026 K30V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4026-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore sealed full-complement V executions (720/1120 kN vs 550/830 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore steel-caged executions (720/1120 kN vs 620/930 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-K30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and 1:30 tapered-bore K30 steel-caged executions (720/1120 kN vs 620/930 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4026-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 130×200×69 mm ISO 15 envelope and equivalent catalogue C/C0; C 4026 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24026",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CC/W33, but catalogue C/C0 differ (720/1120 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24026-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×200×69 mm envelope as the SKF spherical roller bearing SKF 24026 CCK30/W33, but catalogue C/C0 differ (720/1120 kN vs 569/815 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4026-K30V",
      "C 4026 K30V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4126-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4126-2CS5V/GEM9",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 210,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 750,
    "static_load_kN": 1100,
    "fatigue_load_limit_kN": 108,
    "limiting_speed_rpm": 70,
    "max_rpm": 70,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4126-2CS5V/GEM9 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 130×210×80 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. SKF builds the CARB order number from size plus execution: the bare number C 4126 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here 2CS5V/GEM9. The cylindrical 130 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 130×210×80 mm are identical — only the mounting method changes. The 10500 g mass over the 130×210×80 mm envelope yields about 5.77 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Sealed executions arrive greased for life: do not wash out the factory fill, and mount seals-clear of the housing shoulder edges. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 80 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 750/1100 kN ratings belong to this exact execution (C 4126-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Never use C 4126-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 750/1100 kN ratings and 10500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 4126-2CS5V/GEM9 sealed?",
        "a": "Yes — this is a sealed full-complement execution (2CS5V contact seals with annular groove), greased at the factory; the catalogue lists no reference speed and the limiting speed is 70 r/min."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4126-2CS5V/GEM9 have?",
        "a": "A C 4126-2CS5V/GEM9 measures 130 mm bore × 210 mm outside diameter × 80 mm width (5.118 × 8.268 × 3.15 in). From SKF catalogue PUB BU/P1 17000: dynamic C 750 kN, static C0 1100 kN, fatigue limit Pu 108 kN, limiting speed 70 r/min, no reference speed listed, mass about 10500 g."
      },
      {
        "q": "What does C 4126-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 41 the dimension series; the size code gives 130 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24126",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×210×80 mm) SKF spherical roller bearing SKF 24126 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24126 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24126-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×210×80 mm) SKF spherical roller bearing SKF 24126 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24126 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4126-2CS5V-GEM9",
      "C 4126-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2226",
    "brand": "SKF",
    "manufacturer_designation": "C 2226",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 735,
    "static_load_kN": 930,
    "fatigue_load_limit_kN": 91.5,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "weight_g": 11500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2226 is the dimension series 22 CARB toroidal roller bearings member of the CARB range: 130 mm bore, 230 mm OD, 64 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. In C 2226 the 22 dimension series fixes the 230 mm OD and 64 mm width around the 130 mm bore (code 26 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 130 mm seat. Selection arithmetic: C 735 kN against C0 930 kN gives a C0/C ratio of 1.27, and the 91.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 230 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 64 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2226 must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 130 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 735/930 kN ratings and 11500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2226 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 130 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 64 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2226?",
        "a": "A C 2226 measures 130 mm bore × 230 mm outside diameter × 64 mm width (5.118 × 9.055 × 2.52 in). From SKF catalogue PUB BU/P1 17000: dynamic C 735 kN, static C0 930 kN, fatigue limit Pu 91.5 kN, reference speed 2,800 r/min, limiting speed 3,800 r/min, mass about 11500 g."
      },
      {
        "q": "Can a CARB bearing like C 2226 locate the shaft axially?",
        "a": "No — that is the defining feature. C 2226 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2226 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 26 = 130 mm bore (code 26 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2226-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 130×230×64 mm ISO 15 envelope and equivalent catalogue C/C0; C 2226 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22226",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×230×64 mm) SKF spherical roller bearing SKF 22226 E with ratings within 10 % — not a drop-in substitute: SKF 22226 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22226-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×230×64 mm) SKF spherical roller bearing SKF 22226 EK with ratings within 10 % — not a drop-in substitute: SKF 22226 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2226",
      "C 2226"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2226-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2226 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 735,
    "static_load_kN": 930,
    "fatigue_load_limit_kN": 91.5,
    "reference_speed_rpm": 2800,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "weight_g": 11500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2226 K in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. The designation C 2226 K separates into C (CARB), 22 (dimension series), 26 (130 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 130×230×64 mm follows the ISO 15 plan. The K suffix gives a 1:12 tapered 130 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 130×230×64 mm are identical — only the mounting method changes. Selection arithmetic: C 735 kN against C0 930 kN gives a C0/C ratio of 1.27, and the 91.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 64 mm wide cavity does not fill itself.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 64 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 2,800 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 735/930 kN ratings belong to this exact execution (C 2226 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 2226 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 130 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 735/930 kN ratings and 11500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 2226 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2226 K?",
        "a": "A C 2226 K measures 130 mm bore × 230 mm outside diameter × 64 mm width (5.118 × 9.055 × 2.52 in). From SKF catalogue PUB BU/P1 17000: dynamic C 735 kN, static C0 930 kN, fatigue limit Pu 91.5 kN, reference speed 2,800 r/min, limiting speed 3,800 r/min, mass about 11500 g."
      },
      {
        "q": "Can a CARB bearing like C 2226 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2226 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 2226 K designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 26 = 130 mm bore (code 26 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2226",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 130×230×64 mm ISO 15 envelope and equivalent catalogue C/C0; C 2226 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22226",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×230×64 mm) SKF spherical roller bearing SKF 22226 E with ratings within 10 % — not a drop-in substitute: SKF 22226 E locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "22226-EK",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (130×230×64 mm) SKF spherical roller bearing SKF 22226 EK with ratings within 10 % — not a drop-in substitute: SKF 22226 EK locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2226-K",
      "C 2226 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2326-K-VE240",
    "brand": "SKF",
    "manufacturer_designation": "C 2326 K/VE240",
    "series": "C2300-series",
    "type": "carb_toroidal",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 93,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 980,
    "static_load_kN": 1220,
    "fatigue_load_limit_kN": 114,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 27000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 2326 K/VE240 is the dimension series 23 CARB toroidal roller bearings member of the CARB range: 130 mm bore, 280 mm OD, 93 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 2326 K/VE240 separates into C (CARB), 23 (dimension series), 130 mm (slash-size) (130 mm bore — bore 130 mm is written directly after the slash) and K/VE240 (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)); envelope 130×280×93 mm follows the ISO 15 plan. The V suffix denotes a full complement: the toroidal rollers fill the 93 mm space without a cage, raising C to 980 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Selection arithmetic: C 980 kN against C0 1220 kN gives a C0/C ratio of 1.24, and the 114 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: mount on the adapter (H) sleeve matched to the 1:12 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 93 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 130 mm bore, shaft expansion is already measurable: calculate the required float inside the 93 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 2326 K/VE240 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 130 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2326 K/VE240 must float; the two are designed to be used as a pair.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 980/1220 kN ratings and 27000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 2326 K/VE240 designation read?",
        "a": "C = CARB toroidal family; 23 = dimension series; 130 mm (slash-size) = 130 mm bore (the bore is written directly after the slash (no bore code)); suffix K/VE240 selects tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (980 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2326 K/VE240 is the tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 2326 K/VE240 mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2326 K/VE240?",
        "a": "A C 2326 K/VE240 measures 130 mm bore × 280 mm outside diameter × 93 mm width (5.118 × 11.024 × 3.661 in). From SKF catalogue PUB BU/P1 17000: dynamic C 980 kN, static C0 1220 kN, fatigue limit Pu 114 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 27000 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "22326",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×280×93 mm envelope as the SKF spherical roller bearing SKF 22326 CC/W33, but catalogue C/C0 differ (980/1220 kN vs 1176/1320 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22326-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×280×93 mm envelope as the SKF spherical roller bearing SKF 22326 CCK/W33, but catalogue C/C0 differ (980/1220 kN vs 1176/1320 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2326-K-VE240",
      "C 2326 K/VE240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4028-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4028 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 140,
    "D_mm": 210,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 750,
    "static_load_kN": 1220,
    "fatigue_load_limit_kN": 120,
    "limiting_speed_rpm": 800,
    "max_rpm": 800,
    "weight_g": 8600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 4028 V: the toroidal rollers allow the 140 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. In C 4028 V the 40 dimension series fixes the 210 mm OD and 69 mm width around the 140 mm bore (code 28 × 5); the suffix V then selects the cylindrical bore for direct shaft fitting, full-complement V execution (no cage). The cylindrical 140 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 140×210×69 mm are identical — only the mounting method changes. The 8600 g mass over the 140×210×69 mm envelope yields about 5.36 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 750/1220 kN ratings belong to this exact execution (C 4028 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4028 V must float; the two are designed to be used as a pair.",
      "The 750/1220 kN ratings and 8600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 4028 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4028 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4028 V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 28 = 140 mm bore (code 28 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (750 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4028 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4028 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 140 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 69 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4028-K30V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 140×210×69 mm ISO 15 envelope and equivalent catalogue C/C0; C 4028 K30V is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24028",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×210×69 mm envelope as the SKF spherical roller bearing SKF 24028 CC/W33, but catalogue C/C0 differ (750/1220 kN vs 600/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24028-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×210×69 mm envelope as the SKF spherical roller bearing SKF 24028 CCK30/W33, but catalogue C/C0 differ (750/1220 kN vs 600/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4028-V",
      "C 4028 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4028-K30V",
    "brand": "SKF",
    "manufacturer_designation": "C 4028 K30V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 140,
    "D_mm": 210,
    "B_mm": 69,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 750,
    "static_load_kN": 1220,
    "fatigue_load_limit_kN": 120,
    "limiting_speed_rpm": 800,
    "max_rpm": 800,
    "weight_g": 8600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 4028 K30V denotes a toroidal roller bearing whose 69 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. The designation C 4028 K30V separates into C (CARB), 40 (dimension series), 28 (140 mm bore) and K30V (tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)); envelope 140×210×69 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 140 mm shaft deflects; no reference speed is listed and the limiting speed is 800 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 800 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 69 mm wide cavity does not fill itself.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 69 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 750/1220 kN ratings belong to this exact execution (C 4028 K30V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4028 K30V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 140 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 750/1220 kN ratings and 8600 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 4028 K30V?",
        "a": "A C 4028 K30V measures 140 mm bore × 210 mm outside diameter × 69 mm width (5.512 × 8.268 × 2.717 in). From SKF catalogue PUB BU/P1 17000: dynamic C 750 kN, static C0 1220 kN, fatigue limit Pu 120 kN, limiting speed 800 r/min, no reference speed listed, mass about 8600 g."
      },
      {
        "q": "Can a CARB bearing like C 4028 K30V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4028 K30V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4028 K30V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 28 = 140 mm bore (code 28 × 5); suffix K30V selects tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (750 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4028 K30V is the tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4028-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 140×210×69 mm ISO 15 envelope and equivalent catalogue C/C0; C 4028 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24028",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×210×69 mm envelope as the SKF spherical roller bearing SKF 24028 CC/W33, but catalogue C/C0 differ (750/1220 kN vs 600/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24028-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×210×69 mm envelope as the SKF spherical roller bearing SKF 24028 CCK30/W33, but catalogue C/C0 differ (750/1220 kN vs 600/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4028-K30V",
      "C 4028 K30V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4128-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4128-2CS5V/GEM9",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 140,
    "D_mm": 225,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 780,
    "static_load_kN": 1200,
    "fatigue_load_limit_kN": 116,
    "limiting_speed_rpm": 63,
    "max_rpm": 63,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4128-2CS5V/GEM9 in the dimension series 41 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. SKF builds the CARB order number from size plus execution: the bare number C 4128 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here 2CS5V/GEM9. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 140 mm seat. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 85 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 85 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 140 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 780/1200 kN ratings belong to this exact execution (C 4128-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4128-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 780/1200 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 4128-2CS5V/GEM9 sealed?",
        "a": "Yes — this is a sealed full-complement execution (2CS5V contact seals with annular groove), greased at the factory; the catalogue lists no reference speed and the limiting speed is 63 r/min."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4128-2CS5V/GEM9 have?",
        "a": "A C 4128-2CS5V/GEM9 measures 140 mm bore × 225 mm outside diameter × 85 mm width (5.512 × 8.858 × 3.346 in). From SKF catalogue PUB BU/P1 17000: dynamic C 780 kN, static C0 1200 kN, fatigue limit Pu 116 kN, limiting speed 63 r/min, no reference speed listed, mass about 12500 g."
      },
      {
        "q": "What does C 4128-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 41 the dimension series; the size code gives 140 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4128-V-VE240",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 140×225×85 mm ISO 15 envelope and equivalent catalogue C/C0; C 4128 V/VE240 is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24128",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (140×225×85 mm) SKF spherical roller bearing SKF 24128 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24128 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24128-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (140×225×85 mm) SKF spherical roller bearing SKF 24128 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24128 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4128-2CS5V-GEM9",
      "C 4128-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4128-V-VE240",
    "brand": "SKF",
    "manufacturer_designation": "C 4128 V/VE240",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 140,
    "D_mm": 225,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 780,
    "static_load_kN": 1200,
    "fatigue_load_limit_kN": 116,
    "limiting_speed_rpm": 800,
    "max_rpm": 800,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4128 V/VE240 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 140×225×85 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 4128 V/VE240 separates into C (CARB), 41 (dimension series), 140 mm (slash-size) (140 mm bore — bore 140 mm is written directly after the slash) and V/VE240 (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 140×225×85 mm follows the ISO 15 plan. The V suffix denotes a full complement: the toroidal rollers fill the 85 mm space without a cage, raising C to 780 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 85 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 85 mm wide cavity does not fill itself.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 85 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4128 V/VE240 must float; the two are designed to be used as a pair.",
      "Never use C 4128 V/VE240 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 140 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 780/1200 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 4128 V/VE240 designation read?",
        "a": "C = CARB toroidal family; 41 = dimension series; 140 mm (slash-size) = 140 mm bore (the bore is written directly after the slash (no bore code)); suffix V/VE240 selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (780 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4128 V/VE240 is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4128 V/VE240 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 140 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 85 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4128 V/VE240?",
        "a": "A C 4128 V/VE240 measures 140 mm bore × 225 mm outside diameter × 85 mm width (5.512 × 8.858 × 3.346 in). From SKF catalogue PUB BU/P1 17000: dynamic C 780 kN, static C0 1200 kN, fatigue limit Pu 116 kN, limiting speed 800 r/min, no reference speed listed, mass about 12500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4128-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 140×225×85 mm ISO 15 envelope and equivalent catalogue C/C0; C 4128-2CS5V/GEM9 is the cylindrical-bore sealed full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24128",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (140×225×85 mm) SKF spherical roller bearing SKF 24128 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24128 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24128-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (140×225×85 mm) SKF spherical roller bearing SKF 24128 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24128 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4128-V-VE240",
      "C 4128 V/VE240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2228",
    "brand": "SKF",
    "manufacturer_designation": "C 2228",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 830,
    "static_load_kN": 1060,
    "fatigue_load_limit_kN": 102,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 14000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 2228 in the dimension series 22 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. The designation C 2228 separates into C (CARB), 22 (dimension series), 28 (140 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 140×250×68 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 140 mm seat. Selection arithmetic: C 830 kN against C0 1060 kN gives a C0/C ratio of 1.28, and the 102 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: slide the bearing onto the 140 mm seat or heat it (max 120 °C) and seat it square; never press through the 68 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 68 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 830/1060 kN ratings belong to this exact execution (C 2228); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 2228 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 830/1060 kN ratings and 14000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 2228 designation read?",
        "a": "C = CARB toroidal family; 22 = dimension series; 28 = 140 mm bore (code 28 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (830 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2228 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 2228 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 140 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 68 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 2228?",
        "a": "A C 2228 measures 140 mm bore × 250 mm outside diameter × 68 mm width (5.512 × 9.843 × 2.677 in). From SKF catalogue PUB BU/P1 17000: dynamic C 830 kN, static C0 1060 kN, fatigue limit Pu 102 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 14000 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2228-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 140×250×68 mm ISO 15 envelope and equivalent catalogue C/C0; C 2228 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22228",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×250×68 mm envelope as the SKF spherical roller bearing SKF 22228 CC/W33, but catalogue C/C0 differ (830/1060 kN vs 743/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22228-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×250×68 mm envelope as the SKF spherical roller bearing SKF 22228 CCK/W33, but catalogue C/C0 differ (830/1060 kN vs 743/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2228",
      "C 2228"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2228-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2228 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 830,
    "static_load_kN": 1060,
    "fatigue_load_limit_kN": 102,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 14000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2228 K combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 140 mm bore, 250 mm outside diameter, 68 mm wide unit rated 830 kN dynamic. SKF builds the CARB order number from size plus execution: the bare number C 2228 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 140 mm shaft deflects; the 2,400 r/min reference and 3,200 r/min limiting speed are both catalogue values. Speed planning separates the 2,400 r/min thermal reference from the 3,200 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 68 mm wide cavity does not fill itself.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 68 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2228 K must float; the two are designed to be used as a pair.",
      "Never use C 2228 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 140 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 830/1060 kN ratings and 14000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2228 K have?",
        "a": "A C 2228 K measures 140 mm bore × 250 mm outside diameter × 68 mm width (5.512 × 9.843 × 2.677 in). From SKF catalogue PUB BU/P1 17000: dynamic C 830 kN, static C0 1060 kN, fatigue limit Pu 102 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 14000 g."
      },
      {
        "q": "What does C 2228 K mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 140 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 2228 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2228",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 140×250×68 mm ISO 15 envelope and equivalent catalogue C/C0; C 2228 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22228",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×250×68 mm envelope as the SKF spherical roller bearing SKF 22228 CC/W33, but catalogue C/C0 differ (830/1060 kN vs 743/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22228-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×250×68 mm envelope as the SKF spherical roller bearing SKF 22228 CCK/W33, but catalogue C/C0 differ (830/1060 kN vs 743/900 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2228-K",
      "C 2228 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3030-MB",
    "brand": "SKF",
    "manufacturer_designation": "C 3030 MB",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 540,
    "static_load_kN": 850,
    "fatigue_load_limit_kN": 81.5,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 8450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3030 MB is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 150×225×56 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (30) encode the 150 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 150 mm seat. Selection arithmetic: C 540 kN against C0 850 kN gives a C0/C ratio of 1.57, and the 81.5 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: slide the bearing onto the 150 mm seat or heat it (max 120 °C) and seat it square; never press through the 56 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 56 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 540/850 kN ratings belong to this exact execution (C 3030 MB); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 540/850 kN ratings and 8450 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 3030 MB used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3030 MB sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3030 MB have?",
        "a": "A C 3030 MB measures 150 mm bore × 225 mm outside diameter × 56 mm width (5.906 × 8.858 × 2.205 in). From SKF catalogue PUB BU/P1 17000: dynamic C 540 kN, static C0 850 kN, fatigue limit Pu 81.5 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 8450 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3030-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore full-complement V executions (540/850 kN vs 585/960 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C3030-KV",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and 1:12 tapered-bore K full-complement V executions (540/850 kN vs 585/960 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "23030",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope as the SKF spherical roller bearing SKF 23030 CC/W33, but catalogue C/C0 differ (540/850 kN vs 531/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23030-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope as the SKF spherical roller bearing SKF 23030 CCK/W33, but catalogue C/C0 differ (540/850 kN vs 531/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3030-MB",
      "C 3030 MB"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3030-V",
    "brand": "SKF",
    "manufacturer_designation": "C 3030 V",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 585,
    "static_load_kN": 960,
    "fatigue_load_limit_kN": 93,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "weight_g": 8000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3030 V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 150×225×56 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (30) encode the 150 mm bore; suffixes describe bore and execution. The V suffix denotes a full complement: the toroidal rollers fill the 56 mm space without a cage, raising C to 585 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 1,000 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 225 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 56 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3030 V must float; the two are designed to be used as a pair.",
      "Never use C 3030 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 585/960 kN ratings and 8000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 3030 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3030 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3030 V have?",
        "a": "A C 3030 V measures 150 mm bore × 225 mm outside diameter × 56 mm width (5.906 × 8.858 × 2.205 in). From SKF catalogue PUB BU/P1 17000: dynamic C 585 kN, static C0 960 kN, fatigue limit Pu 93 kN, limiting speed 1,000 r/min, no reference speed listed, mass about 8000 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3030-MB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore MB inner-ring-guided brass-caged executions (585/960 kN vs 540/850 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C3030-KV",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×225×56 mm ISO 15 envelope and equivalent catalogue C/C0; C 3030 KV is the 1:12 tapered-bore K full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23030",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope as the SKF spherical roller bearing SKF 23030 CC/W33, but catalogue C/C0 differ (585/960 kN vs 531/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23030-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope as the SKF spherical roller bearing SKF 23030 CCK/W33, but catalogue C/C0 differ (585/960 kN vs 531/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3030-V",
      "C 3030 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3030-KV",
    "brand": "SKF",
    "manufacturer_designation": "C 3030 KV",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 585,
    "static_load_kN": 960,
    "fatigue_load_limit_kN": 93,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "weight_g": 8000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 3030 KV denotes a toroidal roller bearing whose 56 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. SKF builds the CARB order number from size plus execution: the bare number C 3030 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KV. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 150 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 3030 KV deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 225 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 56 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 585/960 kN ratings belong to this exact execution (C 3030 KV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 585/960 kN ratings and 8000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 3030 KV sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3030 KV have?",
        "a": "A C 3030 KV measures 150 mm bore × 225 mm outside diameter × 56 mm width (5.906 × 8.858 × 2.205 in). From SKF catalogue PUB BU/P1 17000: dynamic C 585 kN, static C0 960 kN, fatigue limit Pu 93 kN, limiting speed 1,000 r/min, no reference speed listed, mass about 8000 g."
      },
      {
        "q": "What does C 3030 KV mean in SKF part numbering?",
        "a": "C marks CARB; 30 the dimension series; the size code gives 150 mm bore; KV is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3030-MB",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope, but catalogue C/C0 differ between the 1:12 tapered-bore K full-complement V and cylindrical-bore MB inner-ring-guided brass-caged executions (585/960 kN vs 540/850 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C3030-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×225×56 mm ISO 15 envelope and equivalent catalogue C/C0; C 3030 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23030",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope as the SKF spherical roller bearing SKF 23030 CC/W33, but catalogue C/C0 differ (585/960 kN vs 531/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23030-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×56 mm envelope as the SKF spherical roller bearing SKF 23030 CCK/W33, but catalogue C/C0 differ (585/960 kN vs 531/750 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3030-KV",
      "C 3030 KV"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4030-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4030-2CS5V/GEM9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 585,
    "static_load_kN": 965,
    "fatigue_load_limit_kN": 93,
    "limiting_speed_rpm": 63,
    "max_rpm": 63,
    "weight_g": 10000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 4030-2CS5V/GEM9: the toroidal rollers allow the 150 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (150 mm (slash-size)) encode the 150 mm bore; suffixes describe bore and execution. The 2CS5V/GEM9 execution adds nitrile contact seals on both sides plus an annular-groove relubrication feature and a high-viscosity grease fill; the full-complement rollers keep 585 kN dynamic at a reduced 63 r/min ceiling. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4030-2CS5V/GEM9 deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 75 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4030-2CS5V/GEM9 must float; the two are designed to be used as a pair.",
      "The 585/965 kN ratings and 10000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 4030-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 150 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4030-2CS5V/GEM9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4030-2CS5V/GEM9 sealed?",
        "a": "Yes — this is a sealed full-complement execution (2CS5V contact seals with annular groove), greased at the factory; the catalogue lists no reference speed and the limiting speed is 63 r/min."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4030-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (585/965 kN vs 780/1320 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4030-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and 1:30 tapered-bore K30 full-complement V executions (585/965 kN vs 780/1320 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24030",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope as the SKF spherical roller bearing SKF 24030 CC/W33, but catalogue C/C0 differ (585/965 kN vs 680/1040 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24030-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope as the SKF spherical roller bearing SKF 24030 CCK30/W33, but catalogue C/C0 differ (585/965 kN vs 680/1040 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4030-2CS5V-GEM9",
      "C 4030-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4030-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4030 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 780,
    "static_load_kN": 1320,
    "fatigue_load_limit_kN": 127,
    "limiting_speed_rpm": 750,
    "max_rpm": 750,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4030 V belongs to the CARB family — compact aligning roller bearings: envelope 150×225×75 mm, radial rating 780/1320 kN C/C0, and no axial-locating function by design. The designation C 4030 V separates into C (CARB), 40 (dimension series), 30 (150 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 150×225×75 mm follows the ISO 15 plan. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 150 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4030 V deliberately carries none. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 75 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 780/1320 kN ratings belong to this exact execution (C 4030 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Never use C 4030 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 780/1320 kN ratings and 10500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 4030 V mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 150 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 75 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4030 V?",
        "a": "A C 4030 V measures 150 mm bore × 225 mm outside diameter × 75 mm width (5.906 × 8.858 × 2.953 in). From SKF catalogue PUB BU/P1 17000: dynamic C 780 kN, static C0 1320 kN, fatigue limit Pu 127 kN, limiting speed 750 r/min, no reference speed listed, mass about 10500 g."
      },
      {
        "q": "Can a CARB bearing like C 4030 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4030 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4030 V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 30 = 150 mm bore (code 30 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4030-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (780/1320 kN vs 585/965 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4030-K30V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×225×75 mm ISO 15 envelope and equivalent catalogue C/C0; C 4030 K30V is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24030",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope as the SKF spherical roller bearing SKF 24030 CC/W33, but catalogue C/C0 differ (780/1320 kN vs 680/1040 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24030-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope as the SKF spherical roller bearing SKF 24030 CCK30/W33, but catalogue C/C0 differ (780/1320 kN vs 680/1040 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4030-V",
      "C 4030 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4030-K30V",
    "brand": "SKF",
    "manufacturer_designation": "C 4030 K30V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 780,
    "static_load_kN": 1320,
    "fatigue_load_limit_kN": 127,
    "limiting_speed_rpm": 750,
    "max_rpm": 750,
    "weight_g": 10500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4030 K30V is the dimension series 40 CARB toroidal roller bearings member of the CARB range: 150 mm bore, 225 mm OD, 75 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 4030 K30V separates into C (CARB), 40 (dimension series), 30 (150 mm bore) and K30V (tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)); envelope 150×225×75 mm follows the ISO 15 plan. The V suffix denotes a full complement: the toroidal rollers fill the 75 mm space without a cage, raising C to 780 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 75 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 75 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 4030 K30V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4030 K30V must float; the two are designed to be used as a pair.",
      "The 780/1320 kN ratings and 10500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 4030 K30V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4030 K30V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4030 K30V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 30 = 150 mm bore (code 30 × 5); suffix K30V selects tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (780 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4030 K30V is the tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4030 K30V mounted?",
        "a": "The tapered 1:30 bore mounts on a withdrawal (AH) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4030-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore sealed full-complement V executions (780/1320 kN vs 585/965 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4030-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×225×75 mm ISO 15 envelope and equivalent catalogue C/C0; C 4030 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24030",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope as the SKF spherical roller bearing SKF 24030 CC/W33, but catalogue C/C0 differ (780/1320 kN vs 680/1040 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24030-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×75 mm envelope as the SKF spherical roller bearing SKF 24030 CCK30/W33, but catalogue C/C0 differ (780/1320 kN vs 680/1040 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4030-K30V",
      "C 4030 K30V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3130",
    "brand": "SKF",
    "manufacturer_designation": "C 3130",
    "series": "C3100-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 880,
    "static_load_kN": 1290,
    "fatigue_load_limit_kN": 122,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 15500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 3130 in the dimension series 31 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. The designation C 3130 separates into C (CARB), 31 (dimension series), 30 (150 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 150×250×80 mm follows the ISO 15 plan. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 150×250 mm size with 880 kN dynamic and a 2,000 r/min reference speed. The 15500 g mass over the 150×250×80 mm envelope yields about 5.87 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 80 mm wide cavity does not fill itself.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 2,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 880/1290 kN ratings belong to this exact execution (C 3130); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3130 must float; the two are designed to be used as a pair.",
      "The 880/1290 kN ratings and 15500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is the C 3130 designation read?",
        "a": "C = CARB toroidal family; 31 = dimension series; 30 = 150 mm bore (code 30 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (880 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 3130 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 3130 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 150 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 80 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 3130?",
        "a": "A C 3130 measures 150 mm bore × 250 mm outside diameter × 80 mm width (5.906 × 9.843 × 3.15 in). From SKF catalogue PUB BU/P1 17000: dynamic C 880 kN, static C0 1290 kN, fatigue limit Pu 122 kN, reference speed 2,000 r/min, limiting speed 2,800 r/min, mass about 15500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3130-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×250×80 mm ISO 15 envelope and equivalent catalogue C/C0; C 3130 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23130",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (150×250×80 mm) SKF spherical roller bearing SKF 23130 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23130 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23130-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (150×250×80 mm) SKF spherical roller bearing SKF 23130 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23130 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3130",
      "C 3130"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3130-K",
    "brand": "SKF",
    "manufacturer_designation": "C 3130 K",
    "series": "C3100-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 880,
    "static_load_kN": 1290,
    "fatigue_load_limit_kN": 122,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 15500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 3130 K: the toroidal rollers allow the 150 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (31) identify the ISO dimension series and the last two (30) encode the 150 mm bore; suffixes describe bore and execution. The K suffix gives a 1:12 tapered 150 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 150×250×80 mm are identical — only the mounting method changes. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 3130 K deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 250 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 880/1290 kN ratings belong to this exact execution (C 3130 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3130 K must float; the two are designed to be used as a pair.",
      "Never use C 3130 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 880/1290 kN ratings and 15500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3130 K have?",
        "a": "A C 3130 K measures 150 mm bore × 250 mm outside diameter × 80 mm width (5.906 × 9.843 × 3.15 in). From SKF catalogue PUB BU/P1 17000: dynamic C 880 kN, static C0 1290 kN, fatigue limit Pu 122 kN, reference speed 2,000 r/min, limiting speed 2,800 r/min, mass about 15500 g."
      },
      {
        "q": "What does C 3130 K mean in SKF part numbering?",
        "a": "C marks CARB; 31 the dimension series; the size code gives 150 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 3130 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3130",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×250×80 mm ISO 15 envelope and equivalent catalogue C/C0; C 3130 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23130",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (150×250×80 mm) SKF spherical roller bearing SKF 23130 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23130 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23130-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (150×250×80 mm) SKF spherical roller bearing SKF 23130 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23130 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3130-K",
      "C 3130 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4130-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4130 V",
    "series": "C4100-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 100,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 1220,
    "static_load_kN": 1860,
    "fatigue_load_limit_kN": 176,
    "limiting_speed_rpm": 450,
    "max_rpm": 450,
    "weight_g": 20000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4130 V is the dimension series 41 CARB toroidal roller bearings member of the CARB range: 150 mm bore, 250 mm OD, 100 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 4130 V separates into C (CARB), 41 (dimension series), 30 (150 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 150×250×100 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 150 mm shaft deflects; no reference speed is listed and the limiting speed is 450 r/min. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 450 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Mounting: slide the bearing onto the 150 mm seat or heat it (max 120 °C) and seat it square; never press through the 100 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 100 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 4130 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4130 V must float; the two are designed to be used as a pair.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 1220/1860 kN ratings and 20000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 4130 V?",
        "a": "A C 4130 V measures 150 mm bore × 250 mm outside diameter × 100 mm width (5.906 × 9.843 × 3.937 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1220 kN, static C0 1860 kN, fatigue limit Pu 176 kN, limiting speed 450 r/min, no reference speed listed, mass about 20000 g."
      },
      {
        "q": "Can a CARB bearing like C 4130 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4130 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4130 V designation read?",
        "a": "C = CARB toroidal family; 41 = dimension series; 30 = 150 mm bore (code 30 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (1220 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4130 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24130",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×250×100 mm envelope as the SKF spherical roller bearing SKF 24130 CC/W33, but catalogue C/C0 differ (1220/1860 kN vs 1054/1530 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24130-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×250×100 mm envelope as the SKF spherical roller bearing SKF 24130 CCK30/W33, but catalogue C/C0 differ (1220/1860 kN vs 1054/1530 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4130-V",
      "C 4130 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2230",
    "brand": "SKF",
    "manufacturer_designation": "C 2230",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 980,
    "static_load_kN": 1220,
    "fatigue_load_limit_kN": 114,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 18000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2230: the toroidal rollers allow the 150 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (30) encode the 150 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 150 mm seat. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 73 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 73 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2230 must float; the two are designed to be used as a pair.",
      "Never use C 2230 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 150 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 980/1220 kN ratings and 18000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 2230 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 2230 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2230 have?",
        "a": "A C 2230 measures 150 mm bore × 270 mm outside diameter × 73 mm width (5.906 × 10.63 × 2.874 in). From SKF catalogue PUB BU/P1 17000: dynamic C 980 kN, static C0 1220 kN, fatigue limit Pu 114 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 18000 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2230-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×270×73 mm ISO 15 envelope and equivalent catalogue C/C0; C 2230 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22230",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×270×73 mm envelope as the SKF spherical roller bearing SKF 22230 CC/W33, but catalogue C/C0 differ (980/1220 kN vs 898/1080 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22230-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×270×73 mm envelope as the SKF spherical roller bearing SKF 22230 CCK/W33, but catalogue C/C0 differ (980/1220 kN vs 898/1080 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2230",
      "C 2230"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2230-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2230 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 980,
    "static_load_kN": 1220,
    "fatigue_load_limit_kN": 114,
    "reference_speed_rpm": 2400,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "weight_g": 18000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 2230 K denotes a toroidal roller bearing whose 73 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (30) encode the 150 mm bore; suffixes describe bore and execution. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 150×270 mm size with 980 kN dynamic and a 2,400 r/min reference speed. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 2230 K deliberately carries none. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 270 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 150 mm bore, shaft expansion is already measurable: calculate the required float inside the 73 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2230 K must float; the two are designed to be used as a pair.",
      "Never use C 2230 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 980/1220 kN ratings belong to this exact execution (C 2230 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 980/1220 kN ratings and 18000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2230 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2230 K have?",
        "a": "A C 2230 K measures 150 mm bore × 270 mm outside diameter × 73 mm width (5.906 × 10.63 × 2.874 in). From SKF catalogue PUB BU/P1 17000: dynamic C 980 kN, static C0 1220 kN, fatigue limit Pu 114 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 18000 g."
      },
      {
        "q": "What does C 2230 K mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 150 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2230",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 150×270×73 mm ISO 15 envelope and equivalent catalogue C/C0; C 2230 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "22230",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×270×73 mm envelope as the SKF spherical roller bearing SKF 22230 CC/W33, but catalogue C/C0 differ (980/1220 kN vs 898/1080 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "22230-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×270×73 mm envelope as the SKF spherical roller bearing SKF 22230 CCK/W33, but catalogue C/C0 differ (980/1220 kN vs 898/1080 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2230-K",
      "C 2230 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4032",
    "brand": "SKF",
    "manufacturer_designation": "C 4032",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 765,
    "static_load_kN": 1160,
    "fatigue_load_limit_kN": 110,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4032 belongs to the CARB family — compact aligning roller bearings: envelope 160×240×80 mm, radial rating 765/1160 kN C/C0, and no axial-locating function by design. In C 4032 the 40 dimension series fixes the 240 mm OD and 80 mm width around the 160 mm bore (code 32 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 160 mm seat. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4032 deliberately carries none. Mounting: slide the bearing onto the 160 mm seat or heat it (max 120 °C) and seat it square; never press through the 80 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 1,700 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 765/1160 kN ratings belong to this exact execution (C 4032); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 4032 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 765/1160 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 4032 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 160 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 80 mm roller set."
      },
      {
        "q": "What are the dimensions and ratings of the C 4032?",
        "a": "A C 4032 measures 160 mm bore × 240 mm outside diameter × 80 mm width (6.299 × 9.449 × 3.15 in). From SKF catalogue PUB BU/P1 17000: dynamic C 765 kN, static C0 1160 kN, fatigue limit Pu 110 kN, reference speed 1,700 r/min, limiting speed 2,400 r/min, mass about 12500 g."
      },
      {
        "q": "Can a CARB bearing like C 4032 locate the shaft axially?",
        "a": "No — that is the defining feature. C 4032 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4032 designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 32 = 160 mm bore (code 32 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4032-K30",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×240×80 mm ISO 15 envelope and equivalent catalogue C/C0; C 4032 K30 is the 1:30 tapered-bore K30 steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4032-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and cylindrical-bore sealed full-complement V executions (765/1160 kN vs 830/1290 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and cylindrical-bore full-complement V executions (765/1160 kN vs 915/1460 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore steel-caged and 1:30 tapered-bore K30 full-complement V executions (765/1160 kN vs 915/1460 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24032",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×240×80 mm) SKF spherical roller bearing SKF 24032 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24032 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24032-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×240×80 mm) SKF spherical roller bearing SKF 24032 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24032 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4032",
      "C 4032"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4032-K30",
    "brand": "SKF",
    "manufacturer_designation": "C 4032 K30",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 765,
    "static_load_kN": 1160,
    "fatigue_load_limit_kN": 110,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4032 K30 is the dimension series 40 CARB toroidal roller bearings member of the CARB range: 160 mm bore, 240 mm OD, 80 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. SKF builds the CARB order number from size plus execution: the bare number C 4032 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K30. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 160 mm shaft deflects; the 1,700 r/min reference and 2,400 r/min limiting speed are both catalogue values. Selection arithmetic: C 765 kN against C0 1160 kN gives a C0/C ratio of 1.52, and the 110 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 240 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4032 K30 must float; the two are designed to be used as a pair.",
      "Never use C 4032 K30 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The quoted 765/1160 kN ratings belong to this exact execution (C 4032 K30); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 765/1160 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 4032 K30 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4032 K30 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 4032 K30 have?",
        "a": "A C 4032 K30 measures 160 mm bore × 240 mm outside diameter × 80 mm width (6.299 × 9.449 × 3.15 in). From SKF catalogue PUB BU/P1 17000: dynamic C 765 kN, static C0 1160 kN, fatigue limit Pu 110 kN, reference speed 1,700 r/min, limiting speed 2,400 r/min, mass about 12500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4032",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×240×80 mm ISO 15 envelope and equivalent catalogue C/C0; C 4032 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "C4032-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 steel-caged and cylindrical-bore sealed full-complement V executions (765/1160 kN vs 830/1290 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 steel-caged and cylindrical-bore full-complement V executions (765/1160 kN vs 915/1460 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 steel-caged and 1:30 tapered-bore K30 full-complement V executions (765/1160 kN vs 915/1460 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24032",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×240×80 mm) SKF spherical roller bearing SKF 24032 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24032 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24032-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×240×80 mm) SKF spherical roller bearing SKF 24032 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24032 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4032-K30",
      "C 4032 K30"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4032-2CS5V-GEM9",
    "brand": "SKF",
    "manufacturer_designation": "C 4032-2CS5V/GEM9",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 830,
    "static_load_kN": 1290,
    "fatigue_load_limit_kN": 122,
    "limiting_speed_rpm": 60,
    "max_rpm": 60,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4032-2CS5V/GEM9 belongs to the CARB family — compact aligning roller bearings: envelope 160×240×80 mm, radial rating 830/1290 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (160 mm (slash-size)) encode the 160 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 160 mm seat. Selection arithmetic: C 830 kN against C0 1290 kN gives a C0/C ratio of 1.55, and the 122 kN fatigue load limit Pu sets the contamination-adjusted life floor. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4032-2CS5V/GEM9 must float; the two are designed to be used as a pair.",
      "Never use C 4032-2CS5V/GEM9 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 830/1290 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 4032-2CS5V/GEM9 mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 160 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4032-2CS5V/GEM9 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4032-2CS5V/GEM9 sealed?",
        "a": "Yes — this is a sealed full-complement execution (2CS5V contact seals with annular groove), greased at the factory; the catalogue lists no reference speed and the limiting speed is 60 r/min."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4032",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore steel-caged executions (830/1290 kN vs 765/1160 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and 1:30 tapered-bore K30 steel-caged executions (830/1290 kN vs 765/1160 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and cylindrical-bore full-complement V executions (830/1290 kN vs 915/1460 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30V",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore sealed full-complement V and 1:30 tapered-bore K30 full-complement V executions (830/1290 kN vs 915/1460 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "24032",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×240×80 mm) SKF spherical roller bearing SKF 24032 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24032 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "24032-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×240×80 mm) SKF spherical roller bearing SKF 24032 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24032 CCK30/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4032-2CS5V-GEM9",
      "C 4032-2CS5V/GEM9"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4032-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4032 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 915,
    "static_load_kN": 1460,
    "fatigue_load_limit_kN": 140,
    "limiting_speed_rpm": 600,
    "max_rpm": 600,
    "weight_g": 13000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 4032 V: the toroidal rollers allow the 160 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. SKF builds the CARB order number from size plus execution: the bare number C 4032 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here V. The cylindrical 160 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 160×240×80 mm are identical — only the mounting method changes. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 600 r/min. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 240 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4032 V must float; the two are designed to be used as a pair.",
      "Never use C 4032 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 915/1460 kN ratings and 13000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4032 V have?",
        "a": "A C 4032 V measures 160 mm bore × 240 mm outside diameter × 80 mm width (6.299 × 9.449 × 3.15 in). From SKF catalogue PUB BU/P1 17000: dynamic C 915 kN, static C0 1460 kN, fatigue limit Pu 140 kN, limiting speed 600 r/min, no reference speed listed, mass about 13000 g."
      },
      {
        "q": "What does C 4032 V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 160 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4032 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4032 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4032",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore steel-caged executions (915/1460 kN vs 765/1160 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and 1:30 tapered-bore K30 steel-caged executions (915/1460 kN vs 765/1160 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the cylindrical-bore full-complement V and cylindrical-bore sealed full-complement V executions (915/1460 kN vs 830/1290 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×240×80 mm ISO 15 envelope and equivalent catalogue C/C0; C 4032 K30V is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24032",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope as the SKF spherical roller bearing SKF 24032 CC/W33, but catalogue C/C0 differ (915/1460 kN vs 783/1200 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24032-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope as the SKF spherical roller bearing SKF 24032 CCK30/W33, but catalogue C/C0 differ (915/1460 kN vs 783/1200 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4032-V",
      "C 4032 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4032-K30V",
    "brand": "SKF",
    "manufacturer_designation": "C 4032 K30V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 915,
    "static_load_kN": 1460,
    "fatigue_load_limit_kN": 140,
    "limiting_speed_rpm": 600,
    "max_rpm": 600,
    "weight_g": 13000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 4032 K30V is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 160×240×80 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 4032 K30V separates into C (CARB), 40 (dimension series), 32 (160 mm bore) and K30V (tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)); envelope 160×240×80 mm follows the ISO 15 plan. The K30 suffix gives a 1:30 tapered 160 mm bore, mounted on a withdrawal (AH) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 160×240×80 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 80 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: mount on the withdrawal (AH) sleeve matched to the 1:30 tapered bore, drive up to the catalogue reduction and lock the nut; never press through the 80 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 80 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 4032 K30V must float; the two are designed to be used as a pair.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 915/1460 kN ratings and 13000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 4032 K30V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4032 K30V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4032 K30V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 32 = 160 mm bore (code 32 × 5); suffix K30V selects tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (915 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4032 K30V is the tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)."
      },
      {
        "q": "How is C 4032 K30V mounted?",
        "a": "The tapered 1:30 bore mounts on a withdrawal (AH) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4032",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore steel-caged executions (915/1460 kN vs 765/1160 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-K30",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and 1:30 tapered-bore K30 steel-caged executions (915/1460 kN vs 765/1160 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-2CS5V-GEM9",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope, but catalogue C/C0 differ between the 1:30 tapered-bore K30 full-complement V and cylindrical-bore sealed full-complement V executions (915/1460 kN vs 830/1290 kN) — envelope match, not a load-rating equivalent."
      },
      {
        "equiv_sku": "C4032-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×240×80 mm ISO 15 envelope and equivalent catalogue C/C0; C 4032 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24032",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope as the SKF spherical roller bearing SKF 24032 CC/W33, but catalogue C/C0 differ (915/1460 kN vs 783/1200 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24032-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×240×80 mm envelope as the SKF spherical roller bearing SKF 24032 CCK30/W33, but catalogue C/C0 differ (915/1460 kN vs 783/1200 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4032-K30V",
      "C 4032 K30V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3132",
    "brand": "SKF",
    "manufacturer_designation": "C 3132",
    "series": "C3100-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1000,
    "static_load_kN": 1400,
    "fatigue_load_limit_kN": 129,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 21500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 3132 denotes a toroidal roller bearing whose 86 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. In C 3132 the 31 dimension series fixes the 270 mm OD and 86 mm width around the 160 mm bore (code 32 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 160×270 mm size with 1000 kN dynamic and a 1,900 r/min reference speed. The 21500 g mass over the 160×270×86 mm envelope yields about 6.25 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 86 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 3132 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 1,900 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 1000/1400 kN ratings belong to this exact execution (C 3132); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 1000/1400 kN ratings and 21500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 3132?",
        "a": "A C 3132 measures 160 mm bore × 270 mm outside diameter × 86 mm width (6.299 × 10.63 × 3.386 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1000 kN, static C0 1400 kN, fatigue limit Pu 129 kN, reference speed 1,900 r/min, limiting speed 2,600 r/min, mass about 21500 g."
      },
      {
        "q": "Can a CARB bearing like C 3132 locate the shaft axially?",
        "a": "No — that is the defining feature. C 3132 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 3132 designation read?",
        "a": "C = CARB toroidal family; 31 = dimension series; 32 = 160 mm bore (code 32 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (1000 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 3132 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3132-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×270×86 mm ISO 15 envelope and equivalent catalogue C/C0; C 3132 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23132",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×270×86 mm) SKF spherical roller bearing SKF 23132 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23132 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23132-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×270×86 mm) SKF spherical roller bearing SKF 23132 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23132 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3132",
      "C 3132"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3132-K",
    "brand": "SKF",
    "manufacturer_designation": "C 3132 K",
    "series": "C3100-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1000,
    "static_load_kN": 1400,
    "fatigue_load_limit_kN": 129,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 21500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3132 K is the dimension series 31 CARB toroidal roller bearings member of the CARB range: 160 mm bore, 270 mm OD, 86 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. The designation C 3132 K separates into C (CARB), 31 (dimension series), 32 (160 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 160×270×86 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 160 mm shaft deflects; the 1,900 r/min reference and 2,600 r/min limiting speed are both catalogue values. Selection arithmetic: C 1000 kN against C0 1400 kN gives a C0/C ratio of 1.40, and the 129 kN fatigue load limit Pu sets the contamination-adjusted life floor. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 270 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 86 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 3132 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3132 K must float; the two are designed to be used as a pair.",
      "Reference and limiting speeds are different limits: the 1,900 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 1000/1400 kN ratings and 21500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "How is C 3132 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 3132 K?",
        "a": "A C 3132 K measures 160 mm bore × 270 mm outside diameter × 86 mm width (6.299 × 10.63 × 3.386 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1000 kN, static C0 1400 kN, fatigue limit Pu 129 kN, reference speed 1,900 r/min, limiting speed 2,600 r/min, mass about 21500 g."
      },
      {
        "q": "Can a CARB bearing like C 3132 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 3132 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 3132 K designation read?",
        "a": "C = CARB toroidal family; 31 = dimension series; 32 = 160 mm bore (code 32 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3132",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×270×86 mm ISO 15 envelope and equivalent catalogue C/C0; C 3132 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23132",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×270×86 mm) SKF spherical roller bearing SKF 23132 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23132 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23132-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (160×270×86 mm) SKF spherical roller bearing SKF 23132 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23132 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3132-K",
      "C 3132 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3232",
    "brand": "SKF",
    "manufacturer_designation": "C 3232",
    "series": "C3200-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1370,
    "static_load_kN": 1830,
    "fatigue_load_limit_kN": 170,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 29500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3232 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 160×290×104 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 3232 separates into C (CARB), 32 (dimension series), 32 (160 mm bore) and the bare number (cylindrical bore for direct shaft fitting, pressed steel cage); envelope 160×290×104 mm follows the ISO 15 plan. The open execution relies on the housing seals and lubrication system, fed through groove/hole features on the large sizes. Explorer-class heat treatment and the crowned roller profile keep edge stress down when the 160 mm shaft deflects; the 1,800 r/min reference and 2,400 r/min limiting speed are both catalogue values. The 29500 g mass over the 160×290×104 mm envelope yields about 8.56 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 104 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3232 must float; the two are designed to be used as a pair.",
      "Never use C 3232 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 1370/1830 kN ratings and 29500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 3232?",
        "a": "A C 3232 measures 160 mm bore × 290 mm outside diameter × 104 mm width (6.299 × 11.417 × 4.094 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1370 kN, static C0 1830 kN, fatigue limit Pu 170 kN, reference speed 1,800 r/min, limiting speed 2,400 r/min, mass about 29500 g."
      },
      {
        "q": "Can a CARB bearing like C 3232 locate the shaft axially?",
        "a": "No — that is the defining feature. C 3232 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 3232 designation read?",
        "a": "C = CARB toroidal family; 32 = dimension series; 32 = 160 mm bore (code 32 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (1370 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 3232 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3232-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×290×104 mm ISO 15 envelope and equivalent catalogue C/C0; C 3232 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23232",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×290×104 mm envelope as the SKF spherical roller bearing SKF 23232 CC/W33, but catalogue C/C0 differ (1370/1830 kN vs 1281/1660 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23232-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×290×104 mm envelope as the SKF spherical roller bearing SKF 23232 CCK/W33, but catalogue C/C0 differ (1370/1830 kN vs 1281/1660 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3232",
      "C 3232"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3232-K",
    "brand": "SKF",
    "manufacturer_designation": "C 3232 K",
    "series": "C3200-series",
    "type": "carb_toroidal",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1370,
    "static_load_kN": 1830,
    "fatigue_load_limit_kN": 170,
    "reference_speed_rpm": 1800,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 29500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 3232 K in the dimension series 32 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. SKF builds the CARB order number from size plus execution: the bare number C 3232 is the steel-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 160×290 mm size with 1370 kN dynamic and a 1,800 r/min reference speed. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 104 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "hard-particle indentation where oil or grease filtration is inadequate",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 160 mm bore, shaft expansion is already measurable: calculate the required float inside the 104 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3232 K must float; the two are designed to be used as a pair.",
      "Never use C 3232 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 160 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 1370/1830 kN ratings and 29500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 3232 K have?",
        "a": "A C 3232 K measures 160 mm bore × 290 mm outside diameter × 104 mm width (6.299 × 11.417 × 4.094 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1370 kN, static C0 1830 kN, fatigue limit Pu 170 kN, reference speed 1,800 r/min, limiting speed 2,400 r/min, mass about 29500 g."
      },
      {
        "q": "What does C 3232 K mean in SKF part numbering?",
        "a": "C marks CARB; 32 the dimension series; the size code gives 160 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 3232 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3232 K sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3232",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 160×290×104 mm ISO 15 envelope and equivalent catalogue C/C0; C 3232 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23232",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×290×104 mm envelope as the SKF spherical roller bearing SKF 23232 CC/W33, but catalogue C/C0 differ (1370/1830 kN vs 1281/1660 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "23232-CCK-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×290×104 mm envelope as the SKF spherical roller bearing SKF 23232 CCK/W33, but catalogue C/C0 differ (1370/1830 kN vs 1281/1660 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3232-K",
      "C 3232 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3034-M",
    "brand": "SKF",
    "manufacturer_designation": "C 3034 M",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "brass",
    "dynamic_load_kN": 750,
    "static_load_kN": 1080,
    "fatigue_load_limit_kN": 100,
    "reference_speed_rpm": 2200,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 3034 M combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 170 mm bore, 260 mm outside diameter, 67 mm wide unit rated 750 kN dynamic. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (34) encode the 170 mm bore; suffixes describe bore and execution. The M suffix is a one-piece machined brass cage centred on the rollers, supplied for the 170 mm and larger sizes needing robust guidance under heavy load. Selection arithmetic: C 750 kN against C0 1080 kN gives a C0/C ratio of 1.44, and the 100 kN fatigue load limit Pu sets the contamination-adjusted life floor. Mounting: slide the bearing onto the 170 mm seat or heat it (max 120 °C) and seat it square; never press through the 67 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 170 mm bore, shaft expansion is already measurable: calculate the required float inside the 67 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 750/1080 kN ratings belong to this exact execution (C 3034 M); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 3034 M as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 170 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 750/1080 kN ratings and 12500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Why is C 3034 M used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3034 M sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3034 M have?",
        "a": "A C 3034 M measures 170 mm bore × 260 mm outside diameter × 67 mm width (6.693 × 10.236 × 2.638 in). From SKF catalogue PUB BU/P1 17000: dynamic C 750 kN, static C0 1080 kN, fatigue limit Pu 100 kN, reference speed 2,200 r/min, limiting speed 2,800 r/min, mass about 12500 g."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "23034",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (170×260×67 mm) SKF spherical roller bearing SKF 23034 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23034 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23034-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (170×260×67 mm) SKF spherical roller bearing SKF 23034 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23034 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3034-M",
      "C 3034 M"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4034-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4034 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 90,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 1140,
    "static_load_kN": 1860,
    "fatigue_load_limit_kN": 173,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "weight_g": 17500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4034 V in the dimension series 40 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (40) identify the ISO dimension series and the last two (34) encode the 170 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 170 mm seat. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 90 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 170 mm seat or heat it (max 120 °C) and seat it square; never press through the 90 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 170 mm bore, shaft expansion is already measurable: calculate the required float inside the 90 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 1140/1860 kN ratings belong to this exact execution (C 4034 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 170 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 1140/1860 kN ratings and 17500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4034 V have?",
        "a": "A C 4034 V measures 170 mm bore × 260 mm outside diameter × 90 mm width (6.693 × 10.236 × 3.543 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1140 kN, static C0 1860 kN, fatigue limit Pu 173 kN, limiting speed 500 r/min, no reference speed listed, mass about 17500 g."
      },
      {
        "q": "What does C 4034 V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 170 mm bore; V is the execution (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4034 V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4034 V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4034-K30V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 170×260×90 mm ISO 15 envelope and equivalent catalogue C/C0; C 4034 K30V is the 1:30 tapered-bore K30 full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24034",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×260×90 mm envelope as the SKF spherical roller bearing SKF 24034 CC/W33, but catalogue C/C0 differ (1140/1860 kN vs 963/1460 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24034-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×260×90 mm envelope as the SKF spherical roller bearing SKF 24034 CCK30/W33, but catalogue C/C0 differ (1140/1860 kN vs 963/1460 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4034-V",
      "C 4034 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4034-K30V",
    "brand": "SKF",
    "manufacturer_designation": "C 4034 K30V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 90,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 1140,
    "static_load_kN": 1860,
    "fatigue_load_limit_kN": 173,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "weight_g": 17500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 4034 K30V in the dimension series 40 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. SKF builds the CARB order number from size plus execution: the bare number C 4034 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here K30V. The K30 suffix gives a 1:30 tapered 170 mm bore, mounted on a withdrawal (AH) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 170×260×90 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 90 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 260 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 170 mm bore, shaft expansion is already measurable: calculate the required float inside the 90 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 1140/1860 kN ratings belong to this exact execution (C 4034 K30V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Never use C 4034 K30V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 170 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The 1140/1860 kN ratings and 17500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Which dimensions does the C 4034 K30V have?",
        "a": "A C 4034 K30V measures 170 mm bore × 260 mm outside diameter × 90 mm width (6.693 × 10.236 × 3.543 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1140 kN, static C0 1860 kN, fatigue limit Pu 173 kN, limiting speed 500 r/min, no reference speed listed, mass about 17500 g."
      },
      {
        "q": "What does C 4034 K30V mean in SKF part numbering?",
        "a": "C marks CARB; 40 the dimension series; the size code gives 170 mm bore; K30V is the execution (tapered 1:30 bore for withdrawal (AH) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 4034 K30V used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 4034 K30V sealed?",
        "a": "No, it is an open execution relying on the housing seals; the full-complement V design has no thermal reference speed in the catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C4034-V",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 170×260×90 mm ISO 15 envelope and equivalent catalogue C/C0; C 4034 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "24034",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×260×90 mm envelope as the SKF spherical roller bearing SKF 24034 CC/W33, but catalogue C/C0 differ (1140/1860 kN vs 963/1460 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24034-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×260×90 mm envelope as the SKF spherical roller bearing SKF 24034 CCK30/W33, but catalogue C/C0 differ (1140/1860 kN vs 963/1460 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4034-K30V",
      "C 4034 K30V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2234",
    "brand": "SKF",
    "manufacturer_designation": "C 2234",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1270,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 146,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 28000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 2234 combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 170 mm bore, 310 mm outside diameter, 86 mm wide unit rated 1270 kN dynamic. Reading the code: C marks the CARB toroidal family, the first two digits (22) identify the ISO dimension series and the last two (34) encode the 170 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 170 mm seat. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 86 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "condensation pitting in machines that run intermittently in humid environments",
      "abrasive paste forming as dust bypasses the housing seals into the open washer set"
    ],
    "pitfalls": [
      "At 170 mm bore, shaft expansion is already measurable: calculate the required float inside the 86 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 170 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 1,900 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 2234 must float; the two are designed to be used as a pair.",
      "The 1270/1630 kN ratings and 28000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Is the C 2234 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 2234 have?",
        "a": "A C 2234 measures 170 mm bore × 310 mm outside diameter × 86 mm width (6.693 × 12.205 × 3.386 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1270 kN, static C0 1630 kN, fatigue limit Pu 146 kN, reference speed 1,900 r/min, limiting speed 2,600 r/min, mass about 28000 g."
      },
      {
        "q": "What does C 2234 mean in SKF part numbering?",
        "a": "C marks CARB; 22 the dimension series; the size code gives 170 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2234-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 170×310×86 mm ISO 15 envelope and equivalent catalogue C/C0; C 2234 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2234",
      "C 2234"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C2234-K",
    "brand": "SKF",
    "manufacturer_designation": "C 2234 K",
    "series": "C2200-series",
    "type": "carb_toroidal",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1270,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 146,
    "reference_speed_rpm": 1900,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 28000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "For long shafts that grow thermally, SKF supplies C 2234 K: the toroidal rollers allow the 170 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. In C 2234 K the 22 dimension series fixes the 310 mm OD and 86 mm width around the 170 mm bore (code 34 × 5); the suffix K then selects the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 170×310 mm size with 1270 kN dynamic and a 1,900 r/min reference speed. The 28000 g mass over the 170×310×86 mm envelope yields about 7.47 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 310 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "edge loading and premature spalling when the CARB position is blocked from its designed axial float",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "false brinelling and rust-red witness marks on standby machines under external vibration",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 170 mm bore, shaft expansion is already measurable: calculate the required float inside the 86 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 2234 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 170 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "The quoted 1270/1630 kN ratings belong to this exact execution (C 2234 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "The 1270/1630 kN ratings and 28000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (1270 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 2234 K is the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage."
      },
      {
        "q": "How is C 2234 K mounted?",
        "a": "The tapered 1:12 bore mounts on an adapter (H) sleeve with a defined drive-up; heat the bearing to max 120 °C when fitting, support full ring faces, and verify axial float afterwards."
      },
      {
        "q": "What are the dimensions and ratings of the C 2234 K?",
        "a": "A C 2234 K measures 170 mm bore × 310 mm outside diameter × 86 mm width (6.693 × 12.205 × 3.386 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1270 kN, static C0 1630 kN, fatigue limit Pu 146 kN, reference speed 1,900 r/min, limiting speed 2,600 r/min, mass about 28000 g."
      },
      {
        "q": "Can a CARB bearing like C 2234 K locate the shaft axially?",
        "a": "No — that is the defining feature. C 2234 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C2234",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 170×310×86 mm ISO 15 envelope and equivalent catalogue C/C0; C 2234 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C2234-K",
      "C 2234 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3036",
    "brand": "SKF",
    "manufacturer_designation": "C 3036",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 880,
    "static_load_kN": 1340,
    "fatigue_load_limit_kN": 122,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 17000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In SKF catalogue PUB BU/P1 17000, C 3036 denotes a toroidal roller bearing whose 74 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (36) encode the 180 mm bore; suffixes describe bore and execution. The cylindrical 180 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 180×280×74 mm are identical — only the mounting method changes. Speed planning separates the 2,000 r/min thermal reference from the 2,600 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "brass cage pocket wear under marginal lubrication in the large-bore M/MB executions",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 180 mm bore, shaft expansion is already measurable: calculate the required float inside the 74 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 880/1340 kN ratings belong to this exact execution (C 3036); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3036 must float; the two are designed to be used as a pair.",
      "Never use C 3036 as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "The 880/1340 kN ratings and 17000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 864); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What does C 3036 mean in SKF part numbering?",
        "a": "C marks CARB; 30 the dimension series; the size code gives 180 mm bore; the bare number is the execution (cylindrical bore for direct shaft fitting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 3036 used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      },
      {
        "q": "Is the C 3036 sealed?",
        "a": "No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size."
      },
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3036-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 180×280×74 mm ISO 15 envelope and equivalent catalogue C/C0; C 3036 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23036",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (180×280×74 mm) SKF spherical roller bearing SKF 23036 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23036 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23036-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (180×280×74 mm) SKF spherical roller bearing SKF 23036 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23036 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3036",
      "C 3036"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3036-K",
    "brand": "SKF",
    "manufacturer_designation": "C 3036 K",
    "series": "C3000-series",
    "type": "carb_toroidal",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 880,
    "static_load_kN": 1340,
    "fatigue_load_limit_kN": 122,
    "reference_speed_rpm": 2000,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "weight_g": 17000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "SKF lists C 3036 K in the dimension series 30 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (36) encode the 180 mm bore; suffixes describe bore and execution. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 180 mm seat. The 17000 g mass over the 180×280×74 mm envelope yields about 4.89 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 280 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.",
    "applications": [
      "continuous-caster guide rolls and slab-caster segments under heat growth",
      "vibrating screen exciters fitted with the VE240 tolerance execution",
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position"
    ],
    "failure_modes": [
      "roller-end and flange smearing after lubricant starvation at the long roller contacts",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "rolling-contact fatigue spalling after the catalogue L10 life is exhausted",
      "grease churning and overheating when a high-speed thrust position is over-packed"
    ],
    "pitfalls": [
      "At 180 mm bore, shaft expansion is already measurable: calculate the required float inside the 74 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "The quoted 880/1340 kN ratings belong to this exact execution (C 3036 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 180 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the 2,000 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The 880/1340 kN ratings and 17000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 864); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What fails first on a misapplied CARB bearing?",
        "a": "Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running."
      },
      {
        "q": "Which dimensions does the C 3036 K have?",
        "a": "A C 3036 K measures 180 mm bore × 280 mm outside diameter × 74 mm width (7.087 × 11.024 × 2.913 in). From SKF catalogue PUB BU/P1 17000: dynamic C 880 kN, static C0 1340 kN, fatigue limit Pu 122 kN, reference speed 2,000 r/min, limiting speed 2,600 r/min, mass about 17000 g."
      },
      {
        "q": "What does C 3036 K mean in SKF part numbering?",
        "a": "C marks CARB; 30 the dimension series; the size code gives 180 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ."
      },
      {
        "q": "Why is C 3036 K used opposite a spherical roller bearing?",
        "a": "The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3036",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 180×280×74 mm ISO 15 envelope and equivalent catalogue C/C0; C 3036 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23036",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (180×280×74 mm) SKF spherical roller bearing SKF 23036 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23036 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23036-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (180×280×74 mm) SKF spherical roller bearing SKF 23036 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23036 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3036-K",
      "C 3036 K"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C4036-V",
    "brand": "SKF",
    "manufacturer_designation": "C 4036 V",
    "series": "C4000-series",
    "type": "carb_toroidal",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 100,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "none",
    "dynamic_load_kN": 1320,
    "static_load_kN": 2120,
    "fatigue_load_limit_kN": 196,
    "limiting_speed_rpm": 430,
    "max_rpm": 430,
    "weight_g": 23500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The CARB bearing C 4036 V combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 180 mm bore, 280 mm outside diameter, 100 mm wide unit rated 1320 kN dynamic. The designation C 4036 V separates into C (CARB), 40 (dimension series), 36 (180 mm bore) and V (cylindrical bore for direct shaft fitting, full-complement V execution (no cage)); envelope 180×280×100 mm follows the ISO 15 plan. The V suffix denotes a full complement: the toroidal rollers fill the 100 mm space without a cage, raising C to 1320 kN but cutting the speed ceiling (no reference speed is listed) versus the caged size. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 4036 V deliberately carries none. Mounting: slide the bearing onto the 180 mm seat or heat it (max 120 °C) and seat it square; never press through the 100 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.",
    "applications": [
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts",
      "continuous-caster guide rolls and slab-caster segments under heat growth"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "electrical erosion of raceways on VFD-driven shafts without grounding or insulation",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 180 mm bore, shaft expansion is already measurable: calculate the required float inside the 100 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Never use C 4036 V as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.",
      "Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 180 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.",
      "Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 1320/2120 kN ratings belong to this exact execution (C 4036 V); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "The 1320/2120 kN ratings and 23500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 864); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "What are the dimensions and ratings of the C 4036 V?",
        "a": "A C 4036 V measures 180 mm bore × 280 mm outside diameter × 100 mm width (7.087 × 11.024 × 3.937 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1320 kN, static C0 2120 kN, fatigue limit Pu 196 kN, limiting speed 430 r/min, no reference speed listed, mass about 23500 g."
      },
      {
        "q": "Can a CARB bearing like C 4036 V locate the shaft axially?",
        "a": "No — that is the defining feature. C 4036 V deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 4036 V designation read?",
        "a": "C = CARB toroidal family; 40 = dimension series; 36 = 180 mm bore (code 36 × 5); suffix V selects cylindrical bore for direct shaft fitting, full-complement V execution (no cage). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (1320 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 4036 V is the cylindrical bore for direct shaft fitting, full-complement V execution (no cage)."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "24036",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×280×100 mm envelope as the SKF spherical roller bearing SKF 24036 CC/W33, but catalogue C/C0 differ (1320/2120 kN vs 1134/1730 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      },
      {
        "equiv_sku": "24036-CCK30-W33",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×280×100 mm envelope as the SKF spherical roller bearing SKF 24036 CCK30/W33, but catalogue C/C0 differ (1320/2120 kN vs 1134/1730 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C4036-V",
      "C 4036 V"
    ],
    "locale_variants": {}
  },
  {
    "sku": "C3136",
    "brand": "SKF",
    "manufacturer_designation": "C 3136",
    "series": "C3100-series",
    "type": "carb_toroidal",
    "d_mm": 180,
    "D_mm": 300,
    "B_mm": 96,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1250,
    "static_load_kN": 1730,
    "fatigue_load_limit_kN": 156,
    "reference_speed_rpm": 1700,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "weight_g": 26500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "C 3136 is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 180×300×96 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. In C 3136 the 31 dimension series fixes the 300 mm OD and 96 mm width around the 180 mm bore (code 36 × 5); the suffix the bare number then selects the cylindrical bore for direct shaft fitting, pressed steel cage. The unsuffixed execution carries a pressed steel window cage — the balanced standard for the 180×300 mm size with 1250 kN dynamic and a 1,700 r/min reference speed. The 26500 g mass over the 180×300×96 mm envelope yields about 6.94 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.",
    "applications": [
      "long fan and kiln main shafts where the free end must float without thrust load",
      "heavy industrial gearbox layshafts used as the non-locating position",
      "winder and reel drums in paper and steel strip plants",
      "paper machine drying cylinders and calender rolls with long, thermally expanding shafts"
    ],
    "failure_modes": [
      "raceway spalling once the catalogue L10 life is exceeded or after sustained overload",
      "thermal preloading when a shaft is located at both ends and growth has nowhere to go",
      "PA66 cage (TN9) softening when the sustained temperature passes the polymer limit",
      "brinelling of washer raceways from impact or mounting force applied through the rolling elements",
      "oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips"
    ],
    "pitfalls": [
      "At 180 mm bore, shaft expansion is already measurable: calculate the required float inside the 96 mm wide bearing rather than assuming the free-end clearance is \"enough\" at operating temperature.",
      "Reference and limiting speeds are different limits: the 1,700 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.",
      "The quoted 1250/1730 kN ratings belong to this exact execution (C 3136); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.",
      "Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.",
      "Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3136 must float; the two are designed to be used as a pair.",
      "The 1250/1730 kN ratings and 26500 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 864); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only."
    ],
    "faq": [
      {
        "q": "Can a CARB bearing like C 3136 locate the shaft axially?",
        "a": "No — that is the defining feature. C 3136 deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust."
      },
      {
        "q": "How is the C 3136 designation read?",
        "a": "C = CARB toroidal family; 31 = dimension series; 36 = 180 mm bore (code 36 × 5); suffix the bare number selects cylindrical bore for direct shaft fitting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve."
      },
      {
        "q": "What is the difference between V and TN9 CARB executions?",
        "a": "V is the full-complement execution with no cage — more rollers, higher C (1250 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 3136 is the cylindrical bore for direct shaft fitting, pressed steel cage."
      },
      {
        "q": "How is C 3136 mounted?",
        "a": "Slide or heat (max 120 °C) the bearing onto the 180 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 96 mm roller set."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "C3136-K",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 180×300×96 mm ISO 15 envelope and equivalent catalogue C/C0; C 3136 K is the 1:12 tapered-bore K steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ."
      },
      {
        "equiv_sku": "23136",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (180×300×96 mm) SKF spherical roller bearing SKF 23136 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23136 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      },
      {
        "equiv_sku": "23136-CCK-W33",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Envelope-identical (180×300×96 mm) SKF spherical roller bearing SKF 23136 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23136 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair."
      }
    ],
    "source_ref": "https://www.skf.com/group/products/rolling-bearings",
    "catalog_ver": "SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings",
    "extracted_at": "2026-09-27",
    "last_verified": "2026-09-27",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "C3136",
      "C 3136"
    ],
    "locale_variants": {}
  }
]